Ben Mendelsohn was 16 in The Still Point when he played the character 'Peter'.
That was over 37 years ago in 1986.
This was his first recorded movie acting credit (although may not technically be his first actual acting role).
Today he is 53, and has starred in 65 movies in total, 62 of those since The Still Point was released.
In The Still Point, I think Ben Mendelsohn looks: