Well, I don't whistle, and I don't snap my fingers. But I like spicy food, and I do tend to drink a lot of water. I say "thank you" every time the waiter fills my glass. And if my glass stands empty for a prolonged time, or if I have to politely ask for a refill, this will always be reflected in the tip.
“9. Oh, you needed more water so badly, you had to snap or tap or whistle? Ill be right back in ten minutes”
That’s the problem: It’s already been ten minutes.