TOD:
They do make me laugh these days:
Every dog has its day. - Well, sure, it goes to sleep and has a day when it wakes up, right?
A stitch in time saves nine. - Saves nine what? Pints of blood?
Don't look a gift horse in the mouth. - Is the gift horse like the tooth fairy?
I like the Groucho's versions:
I'd like to dance with you til the cows come home. On second thought, I'd like to dance with the cows til you come home.
Go and never darken my towels again.
I never forget a face, but in your case, I'll make an exception.
Outside of a dog, a book is man's best friend. Inside of a dog, it's too dark to read.
Time flies like an arrow. Fruit flies like a banana.
