David Lynch was 19 in Sailing with Bushnell Keeler when he played an uncredited character.
That was over 57 years ago in 1967.
This was his first recorded movie acting credit (although may not technically be his first actual acting role).
Today he is 78, and has starred in 107 movies in total, 106 of those since Sailing with Bushnell Keeler was released.
In Sailing with Bushnell Keeler, I think David Lynch looks: