Dylan O'Brien was 19 in Charlie Brown: Blockhead's Revenge when he played the character 'Charlie Brown'.
That was over 13 years ago in 2011.
This was his first recorded movie acting credit (although may not technically be his first actual acting role).
Today he is 32, and has starred in 18 movies in total, 15 of those since Charlie Brown: Blockhead's Revenge was released.
In Charlie Brown: Blockhead's Revenge, I think Dylan O'Brien looks: