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 can stop my own hiccups at will 100% of the time
i have always lucid dreamed since as far back as i can remember, i genuinely believed that everyone experienced sleep like that until i was in my mid-twenties