I have a data point/anecdote! I like to play certain sports. After about a year of intense focus and determination, you can get good at pretty much any sport. What I've noticed though is that on a good day, I'm messing up about 15% of the time. If I mess up significantly more than that, I get discouraged and want to go home and try again the next day. If I'm not messing up enough, I feel like I'm overfitting a particular technique and should probably be messing up more to become more well-rounded.