Walter Matthau was 46 in The Odd Couple when he played the character 'Oscar Madison'.
That was over 56 years ago in 1968.
In 2000 he died aged 79, starring in 85 films in his career, 60 of those after The Odd Couple was first released. If he were alive today he would be 103.
In The Odd Couple, I think Walter Matthau looks: