Many of these aren't petty at all.
Pettiest thing I'd do is convert a lot of my money into twenty dollar bills. Pay to have the bills cleaned and pressed because money is effing filthy. Then when my poor friends think out loud to themselves about how they could really use twenty bucks, I would reply twenty bucks? Twenty bucks!? I wipe my ass with twenty dollar bills, lol! I... would not have friends if I were filthy stinking rich. But it's okay, I could buy some new ones! :D
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