Well, trying to tell the same joke twice is itself a kind of humour.
So dont worry, professor. Keep posting....
Here is another one about the psychlogy and sociology of the elderly:
An elderly couple in their mid 90s ask their lawyer to arrange for
Lw: Hey, you have been going strong for all those years, why now?
Were you waiting for your children to grow up and settle down?
Couple: They grew up fine. It was just that we were waiting for
them to die out....
(Not so funny, hey!!!!...0
Suresh Rattan, Aarhus, Denmark rattan at kemi.aau.dk