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 have an excellent sense of time and space, i can accurately tell how much time and distance I’ve gone without tools. Im great to bring along for a hike.
Out of interest, do you have a vague ability to tell orientation (magnetic north) with your eyes closed? Research is showing some people have magnetoreception and that it may have been more common in our human ancestors but lost to many over time.
It could explain why you’re so good at telling distance and time.
If you’re ever bored one night, close your eyes and get a friend to rotate you around (gently and slowly) then get you to turn yourself to point where you feel north is. Do this 10 times, logging how far of you were from north and see how accurate you are from random.
You might have a hidden sense that’s incredibly rare in humans!
Here's a pretty recent paper on this. I only skimmed it but boy does this seem wacky. It is in Nature, though, so I guess it's at least somewhat serious...?