"The definition of insanity is doing the same thing over and over and expecting it to be different this time" the The fly beating his head on the screening is one example.
"If at first you don't succeed try and try again"
I see there is a page on the net with more like:
Birds of a feather flock together.
You're never too old to learn.
You cant teach an old dog new tricks.
Winners never quit
Quit while you're ahead .
The early bird gets the worm
The second mouse gets the cheese.
And,Do unto others as you would have done unto you.
Nice guys finish last.
There are more- I liked these the best.