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 :]
I’m really good at getting cats to vocally respond to me. I don’t know if I’m just on their wavelength or what, but almost every time I start a convo with a kitty I get a response. Oddly specific, but also pretty fun. Kids love it lol.