As originally published in Financial Advisor magazine.

I watched a boxing trainer tell his fighter right before the fight started, “You are a tiger! You are a beast!” The fighter repeated “I am a tiger! I am a beast!” About 30 seconds later, the bell rang, the fight started, and the tiger-beast got brutally knocked out by an opponent who could actually box. The poor tiger had no business in the professional ring, and his coach would have served him well to advise him to train a lot more before joining the ranks of paid fighters rather than feeding him motivational nonsense.

Time and again I work with firm owners who are extremely reluctant to be “the bad guy” and actually deliver to people they manage or mentor the tough but much-needed advice that they aren’t doing as well as they should and that they need to address their weaknesses. This reluctance is so pervasive that it has essentially become part of the culture of the advisory industry. Advisors usually “reframe” career decisions and redesign career tracks rather than simply telling their employees they need to fix a problem, learn more, gain more experience, have more patience or simply put more effort into their career. The result is an abundance of careers that are unsustainable—just waiting for the knockout punch of reality. That punch always comes.

The issue is twofold—managers avoid correcting mistakes for fear of being seen as critical and may even avoid entire areas of development because they will lead to “negative” conversations. Some of the best mentoring advice I have ever received began with the words “You have a problem you have to fix …” Advice such as “Forget your weaknesses, play to your strengths” is very easy to deliver, but also of little use beyond its 30 seconds of inspiration. In fact, the advice can even be harmful (even if it means well) if it comes when people are developing their skills and discovering their talents.

First of all, some weaknesses are fatal. When I was a kid, I had a friend who wanted to be a water polo player. But he couldn’t swim. These days, I often meet managers who believe that “managing” is not their talent or advisors who “are not very good working with people.” My friend the aspiring water polo player who couldn’t swim got laughed at. The manager who couldn’t manage got an understanding nod, even though his problem was equally ridiculous.

There are some skills and abilities that are so fundamental to a professional career that they have to be addressed with a sense of urgency. In professional services, this means people must understand the body of theory they are using, be able to communicate with clients and colleagues, understand team dynamics and be able to participate in and contribute to a team. Any weaknesses in these areas would limit their professional careers or only allow them to thrive in very limited circumstances. When such fundamental weaknesses exist, it is the job—in fact, the responsibility—of a mentor to deliver the bad news and help their mentees change and address the issues.

We all have natural talents, that’s undeniable. But we still have to find what those talents are and develop them, which means we are going to have to hear negative feedback and endure the process of learning. How would you know you are “talented” at learning languages in the first place if you never tried to learn one? How do you know you are not a good manager if you never managed anyone? You won’t learn your strengths until you try, and by that I mean really try.

In her excellent book Grit: The Power of Passion and Perseverance, Angela Duckworth tells the story of her teaching career and how she discovered that her best students in math were not always the talented kids. In fact, talented kids who showed early success often failed to develop above the average level. It was really the kids who day after day came prepared, worked hard and sought help when they needed it. The title of the book gives away the conclusion—the ability to persevere and dedicate effort and passion to a task often outperforms pure talent. I would also propose that it is perseverance that unveils talent. What may look like a weakness may just be a talent that is underdeveloped.

When people criticize negative feedback, they often misunderstand what it means to be a leader. We are surrounded with books and articles advising leaders to inspire. “Inspirational leadership” has become the standard expectation, and certainly no one is inspired by the words “you suck at this.” Inspiring, however, does not mean sugarcoating. In fact, it often means finding a way to motivate people to fix a problem they experience. Everyone is happy to pass out the candy, but eventually someone has to tell the kids that all this candy is not healthy for them. The “cool uncle” is not a leader, your mom is.

A 2014 article by Olga Khazan in The Atlantic referred to a 2000 study of Division I athletes, in which researchers showed that the best results were achieved by coaches who were, as Khazan writes, “neither too easygoing, nor hard-charging—they reinforced consistently, but with a democratic style.” This is key: Corrective feedback does not have to be spirit-crushing and angry-faced, but it does have to be part of a coaching relationship.

Unfortunately, delivering “bad news” is not rewarding, even if it is the right thing to do. The difficult conversation may be met with a defensive and emotional reaction and upset the person you work with. It will certainly not endear you to that person, at least not in the short term. It may create complications and many hours of conversations. It is so much easier to simply focus on the “positive.”

Somehow, the “positive” has become such a cultural force. Everyone has somehow learned that positive reinforcement is better and accepted that truism. Feedback about weaknesses to be corrected or about people lacking skills is labeled as “negative” thinking and frowned upon. We would rather stereotype and rationalize than simply ask people to correct a behavior that they could both be unaware of and absolutely willing to correct. We would rather talk about how “Jennifer is a typical millennial” rather than telling Jennifer that she should not be looking at her cell phone during staff meetings.

While positive feedback is very effective and should be used heavily, nature certainly has made sure we also pay attention to negative feedback. We learn to recognize nettles because they sting. We only touch a hot plate once. Negative reinforcement works pretty well. We ideally don’t need to use it, but sometimes there is no other way to explain why that beautiful-looking black-and-yellow bug that makes the interesting buzzing sound is not really a good pet.

In an article published in the journal Social and Personality Psychology Compass, researchers Ayelet Fishbach, Tal Eyal and Stacey Finkelstein studied students who were learning foreign languages and noticed that while beginners were best motivated by encouragement, advanced students not only welcomed corrections but actively sought them. The authors quote similar research following people who pursued weight loss or training in an athletic skill. The research showed that positive feedback is indeed much better at motivating beginners, but as their study subjects became more advanced, they not only reacted well to but sought negative feedback.

This suggests that if we are managing or mentoring employees very early in their career, we may be best served to ask them to repeat the positive behavior and not dwell excessively on their weaknesses. On the other hand, if we are mentoring employees who are aspiring to be leaders and who are well advanced in their career but still developing, corrective feedback should not only be part of our coaching process but in fact may very well be welcome. There is no reason to correct beginners or those who are about to retire, but everyone else could fix a thing or two.

Actually, the very business owners who fear asking their team members to do something difficult are often perfect examples of the value of perseverance. None of the owners I work with went to Harvard or any other Ivy League school (except for one guy who will tell you that he did within a few minutes of meeting him). They built their careers on very hard work and perseverance. When I talk to firm founders, they never describe themselves as “talented” but instead use terms such as “dedicated,” “competitive” and “willing to learn and do whatever they can.” They are often very open to learning something new and in fact they often ask “What am I doing wrong?” Yet for some reason, they are afraid to ask team members to do the same.

Growth comes out of discomfort. I read somewhere that the famous surfer Laird Hamilton practiced standing with bare feet on golf balls so that he could learn to tolerate the discomfort and pain. On the wall near the canal where the famous University of Washington crew team practices and races, one of the teams wrote “It is a pain contest!” I have seen that same attitude in many of the successful business owners I have worked with. They embrace the discomfort and even take pride in it. They know that the high levels of achievement never come without some pain.

This is not a call for negative attitudes and thinking. You do not have to start your day by making a list of the things you do poorly. Then again, starting your day by telling yourself you are awesome won’t do it either. Nor is this a call to scream at your employees about all the things they are doing wrong. But it is also not a good idea to tell them they are great until the day you fire them for poor performance. If you want your colleagues to develop into successful professionals, as a mentor you have the obligation to help them recognize and fix their weaknesses. You can let yourself be the “bad guy” (or “bad girl”) for an hour or for a day, though, so that someone can really develop into a good professional.