I feel exactly the same. I am still surprised by the broadness and complexity of software projects I engaged in when much younger (under 18). At some point I was writing a videogame (programming a sprite editor from scratch in Borland Pascal, writing the game in Borland C), designing and writing a multi-tasking operating system in Z80 (where I remember having to come up tricks such as pushing the address to jump to on the stack and using "ret" because there was no mechanism to jump to a runtime defined address) and participating in programming contents at the national level (where, in one instance, I "invented" backtracking without even realizing what it was until much later). I could learn a new programming language in a month, write thousands of lines of code in a few more weeks and make connections between the different languages, styles, challenges and come up with solutions based on the broadness of that knowledge. To this day (20 years later) I still reference things I learned back then when I find patterns/similarities in day to day programming work. Haven't been able to broaden my knowledge much since, motivation has taken a huge dive and I spend almost no time at all improving these skills outside of work.