Jonah Hill was 19 in I ♥ Huckabees when he played the character 'Bret Hooten'.
That was over 20 years ago in 2004.
This was his first recorded movie acting credit (although may not technically be his first actual acting role).
Today he is 40, and has starred in 56 movies in total, 52 of those since I ♥ Huckabees was released.
In I ♥ Huckabees, I think Jonah Hill looks: