Last week, investor and finance writer Morgan Housel wrote an essay called Dangerous Feelings.

The first law of hard work is that you expect there to be a payoff. How could it be any other way?

But a dangerous feeling occurs when you want the payoff of years of hard work to be an assumption that you’ve mastered a topic. Or that you don’t need to update your views because you already spent years of hard work learning those views.

You see it all the time in so many industries. Veterans fall behind the younger generation because if veterans admitted that they had to adapt to what the younger generation is doing they’d feel like the hard work they put over their career was for nothing.

Even if you know your field evolves, the idea that what you learned in the past may no longer be relevant is so painful that it’s easy to reject. The longer you’ve been in a field the truer that becomes. It’s hard for a 50-year veteran to admit that a rookie might know as much as he does. But if what the veteran learned 30 or 40 years ago is no longer relevant, it can be true. And the rookie may be more aware of what he doesn’t know, while the veteran is iron-clad sure of his beliefs because he’s worked hard and expects a payoff.

Some things never change, and learning them in one era can help you in the next. But the more your field evolves – the more it involves people’s decisions – the smaller that set of learnings is, and the more you need to fight the urge to think that your long-term experience means you now permanently understand how the field works.

Investor Dean Williams put it: “Expertise is great, but it has a bad side effect. It tends to create an inability to accept new ideas.”

This is something Gordon Ryan talked about on Joe Rogan’s podcast earlier this year about regarding black belts that don’t evolve:

You see a general pattern in jiu-jitsu. You see a guy get to a certain level. He wins a few competitions. There were a few big competitions. Then he coasts on the technique he has. And the only progression that he makes from the age of 25, where he was his first ADCC to the age of 35 is everyone just takes more steroids.

So they just get, they just get bigger and stronger. And then they just coast on the same technique they have. And then by the time that 35 to 40, they peak physically. And then after that, they kind of degenerate and then that’s the end of the career.

I had my weekly private lesson this morning, and when it was over, it was clear that I’m not close to mastery. We reviewed standup techniques that I thought I was quite proficient at already. I wasn’t doing anything “incorrect,” but there was plenty of room for improvement. Half the time I take privates, they’re to review the basics, and often, I learn something that I’d never seen or experienced before, even after nearly ten years of training.

Now, I don’t compete, and neither do 99% of my training partners. But, I do see some that do coast and get stagnant. That’s not to say it really matters, since the number one thing is simply to keep training. However, when our jiu-jitsu stops improving, or others improve more quickly, that can lead to quitting because it can be hard not to compare ourselves (unfavorably) to others.

You’ll never know it all because the art evolves. So instead of trying to be the master of what (you thought) jiu-jitsu was when you started, accept that it’s different now, and keep a beginner’s mind.