Ye gods. Why ask me such things?
I'm 44, and I've been working at being in comics for about 25 years. I've actually been in comics for about 15 years, when I got my first published work. I've been doing webcomics for four years; we launched Hunter Black in July, 2011.
(Jack Kirby started work on the Fantastic Four, co-creating the modern Marvel Universe, at 44. I have to keep reminding myself of that.)