You shouldn't forget the impact of luck and the environment on people. For every successful band in their early 20s there are probably many thousands of better musicians out there that are just getting by. I also know a number of people who were significantly more successful than me at 26, but were unable to sustain that success as the lack of skill and experience reversed their luck in the long run.
For me, 26 was an age where I started to focus on my general productivity. My most productive time initially was in my teens, where I learned and achieved a lot from the age of 15 to 19, so much that it put me well ahead of others my age and really carried me through a comfortable career until I was 26. During those years of working I didn't have a computer at home. I went out, I was rarely at home, I partied a lot, I dated and I developed a lot of social and cultural skills at that time. I did things that didn't count as successful projects, but developed and educated me in so many ways, just like spending years on HN will let you grow a wide body of knowledge but you might end up with nothing to show for it. After 26 I also had enough work experience to land jobs where I had both the skill plus the autonomy to take on interesting and useful projects at work that I could get stuck into. It's only deep into my 30s that I developed the ability to focus and complete projects outside of my working hours.
For me, 26 was an age where I started to focus on my general productivity. My most productive time initially was in my teens, where I learned and achieved a lot from the age of 15 to 19, so much that it put me well ahead of others my age and really carried me through a comfortable career until I was 26. During those years of working I didn't have a computer at home. I went out, I was rarely at home, I partied a lot, I dated and I developed a lot of social and cultural skills at that time. I did things that didn't count as successful projects, but developed and educated me in so many ways, just like spending years on HN will let you grow a wide body of knowledge but you might end up with nothing to show for it. After 26 I also had enough work experience to land jobs where I had both the skill plus the autonomy to take on interesting and useful projects at work that I could get stuck into. It's only deep into my 30s that I developed the ability to focus and complete projects outside of my working hours.