You’re a pretty smart person. No, don’t try to play humble and say you aren’t. You are, and you know it. Maybe you’re really smart, or even a genius. Regardless, you’re probably better at or happier doing some things over others, and with certain activities, you’re lucky enough to get both. The point is, whether it’s a lot about a few things or a little about lots of things: you’ve got some serious knowledge up in that brain.
It didn’t just land there, either. You worked hard to fill that brain up.