Something you’re just good at with minimal effort and/or you learned much more quickly than average.
For me, it’s paper snowflakes. My brain just seems to effortlessly figure out what cuts to make to the paper wedge to make it turn out exactly how I want it. Largely useless, but good fun and was a much-needed ego boost when I was a kid :]
Mathematics, dance, and remembering song lyrics. I passed the first to all of my children and the last to two of them.