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? I’ll be right back … in ten minutes”
That’s the problem: It’s already been ten minutes.