That was over 46 years ago in 1975.
Today he is 84, and has starred in 75 movies in total, 44 since One Flew Over the Cuckoo's Nest was released.
In One Flew Over the Cuckoo's Nest, I think Jack Nicholson looks:
One Flew Over the Cuckoo's Nest scores 8.3 out of 10 on The Movie Database.
Jack Nicholson's first acting role was as 'Jimmy Wallace' in The Cry Baby Killer, released in 1958 when he was 21.