A fine-looking gentleman sat down in the main dining room of an expensive restaurant. He ordered a big dinner and spent an hour enjoying himself.
After he was given the check, he summoned the headwaiter. "Ah, my friend," he said, "that was a delicious meal! Perhaps you don't remember that I was a guest at this same table just about a year ago. And at that time I couldn't pay the check, so you, sir had me thrown out in full view of all the other diners."
"I am so sorry, sir," said the head waiter, "but, you understand-"
"Oh it's quite all right," interrupted the gentleman, "but I'm afraid I'll have to trouble you again."
There is a glass of water on the table.
Optimists think the water in the glass is half full.
Pessimists think the water in the glass is half empty.
Opportunists and Realists like me, drink the water in the glass, put it back on the table, and then leave.