Gaspard Ulliel was 12 in Bonnes vacances when he played the character 'Joël'.
That was over 26 years ago in 1998.
This was his first recorded movie acting credit (although may not technically be his first actual acting role).
In 2022 he died aged just 37, starring in 44 films in his career, 44 of those after Bonnes vacances was first released. If he were alive today he would be 39.
In Bonnes vacances, I think Gaspard Ulliel looks: