One more thing: I think an underrated advantage that adults tend to have over children and teenagers is the ability to understand the scope of a project, plan out that project, and follow that plan. This can be valuable for any artistic project, from a single painting, to a graphic novel. Probably the most common hurdle in art school was that some very talented students just weren't organized enough to hand their assignments in on time. There were students who were far better at drawing than I was, but got worse grades because they were either chronically late to hand things in, or because they would hand in work that, while impressive, didn't really indicate that they understood the assignment. I already had a previous university degree, so I would look at assignment descriptions, say "Oh, I see, the point of the assignment is to learn X" and I would consistently do pretty well, with each completed assignment being something I could add to my portfolio. My ability to manage a project also meant that I was able to complete my 4th-year project on time (a 6-minute film I animated pretty much single-handedly).