I'm pretty stingy with my money. I used to lend money to family in the past. But eventually it turned into a charity with my name on it. I remember writing off $180 my parents promised me as a kid. They completely forgot about it and I still had records years afterward!
I cashed a check for $26.16 at a local bank recently. The teller gave me $5 less than they were supposed to. I never count money in front of people unless I am paying them. So I walked out to the car and counted it 2-3 times. Sure enough, $5 short. She neglected to give me a receipt of any kind so I had no proof of anything.
I bought a car off craigslist and gave the guy cash in an envelope. This guy called me after I left and said I shorted him $150. I almost had a panic attack so I said, "let me call you back." I counted it again in my head and remembered that I had counted it no less than 5 times before I gave him the money(three times at home and twice in the car). Then I realized that no matter how you count it. You cannot short somebody $150 if you pay them the exact amount using hundred dollar bills...