"I've often wondered how one man can shoot 1200 rounds all at once. I'll lurk this thread so maybe someone can brainwash me."
It's the whole principle of stocking up a lot of ammo so that if you're in a situation where you'll really need it, you'll have plenty to go around. I let my stock of ammo get way too low a few months ago, but even though I'm really tight on money I buy a couple of boxes here and there when I get spare change and slowly build up my supplies.
I buy it (9mm & .380) by the case of 1,000 rounds when it goes on sale.