I spent hours one afternoon as a kid trying to figure it out. After a few hours my right (dominant) hand was completely wrecked, but I was so frustrated I just switched to the left hand and kept trying. Eventually I got a passable snapping sound and ran to my mom sobbing with joy to demonstrate the saddest sounding snap. She noticed my hands were shaking and made me sit down and hold them on ice packs, lol.

I’m 29 now and still can’t snap with my dominant hand for shit but my left hand snap sounds decent.