Freddie Prinze Jr. was 19 in To Gillian on Her 37th Birthday when he played the character 'Joey Bost'.
That was over 27 years ago in 1996.
This was his first recorded movie acting credit (although may not technically be his first actual acting role).
Today he is 47, and has starred in 32 movies in total, 30 of those since To Gillian on Her 37th Birthday was released.
In To Gillian on Her 37th Birthday, I think Freddie Prinze Jr. looks: