The expression 'Those who can't do, teach' is a curious one, because if you look at the world , you'll see that teachers aren't particularly worse at doing things than anyone else, so perhaps the expression might be better worded as 'nobody can do anything

Neither were you [born yesterday], unless of course I am wrong, in which case welcome to the world, little baby, and congratulations on learning to read so early in life.

Just about everything in this world is easier said than done, with the exception of 'systematically assisting Sisyphus's stealthy, syst-susceptible sister,' which is easier done than said.

Dumping you times infinity. Still not enough.

Troublesome things tend to remain troublesome no matter how many times you do them.

If you have ever slept in a covered casserole dish on the highest peak of a mountain range, then you know that it is an uncomfortable place to lay one's head, even if you find a dish towel inside it that can serve as a blanket.

Tell it to everyone you know, but pretend you're kidding.