Idk about Big Karma, but Small Karma is real. The other day I was doing laundry and a lady asked for help with how to pay; she'd never been to a laundromat before and she was washing stuff per her work duties. I showed her the touch screen thing, and as she went to start the machine I went to pay. I clicked out of the "do you want a receipt" screen and not a millisecond later she said "they don't give receipts then?" and I said no.
Anyway, because I'm a small time scumbag, my compromised thumbnail has totally snapped off.