When I use a word," Humpty Dumpty said in rather a scornful tone, "it means just what I choose it to mean - neither more nor less.

I can't go back to yesterday - because I was a different person then

We called him Tortoise because he taught us.

She generally gave herself very good advice, (though she very seldom followed it)

But as long as you know you're nobody special, you'll be a very decent sort of Horse, on the whole, and taking one thing with another.

Courtesy while you're thinking what to say. It saves time.