James Cameron was 29 in The Making of the Terminator when he played the character 'Self'.
That was over 39 years ago in 1985.
This was his first recorded movie acting credit (although may not technically be his first actual acting role).
Today he is 69, and has starred in 51 movies in total, 49 of those since The Making of the Terminator was released.
In The Making of the Terminator, I think James Cameron looks: