Hell no. Some people are at their peak at 21, but I was a real loser at that age. I was socially awkward, and very immature for that age, I think. I was in college, getting slightly better than average grades. I had trouble concentrating. I spent altogether too much time and effort chasing girls. I was lonely and unhappy and I didn't get along with my family. I had no self-confidence and I really wondered how I would ever fit into the world and make a living.
It's been decades since then. I've come a long way but really only in the last few years. I'm smarter, better-adjusted to my environment, much happier, all that stuff.