It has nothing to do with the humour becoming dated. It has to do with the humour being fresh. Humour by definition involves people suprising you. People you kn

It has nothing to do with the humour becoming dated. It has to do with the humour being fresh. Humour by definition involves people suprising you. People you know very well have a much lesser ability to surprise you, and their attempts at humour fade from make you roll on the floor with laughter to simply smiling. Comedy has to stay fresh and constantly reinvent itself. It has to run to stay at the same spot.