I don't think 11yr vs 15yr/16yr is a big difference for measuring. I started early, probably falling into 11yr category. Many years passed, and recently I had a

I don't think 11yr vs 15yr/16yr is a big difference for measuring. I started early, probably falling into 11yr category. Many years passed, and recently I had a chance to look at my code of the age probably around 20. There were so many wrongs in the code that I stopped counting. Definitely I learned a lot since then. So the period between 11yr and 21yr was just fun for coding and getting things working as quickly as possible (youth just can not wait).