I cannot tell you how many towels the average person uses, or what the distribution is. Though it's probably less than 4. What I can say is that it doesn't hurt anybody, so if it feels good for you, just do it. That's the nice thing about being an adult, you can do what you want.
I would note though that it's probably much more important how often you change and wash your towels than how many you use.
Gnumeric, not because of it's features but just because it's so ridiculously fast