It came to me while drinking my coffee:

I figured out my answer to the question:

If you could have one superpower, what would it be?

My answer?

To be able to get any thing I reach for, in a timely manner.

And yes, I'm limiting it to concrete things-- not concepts or goals (like, say: "Convince world leaders to give up war," or "My perfect love partner."

But I am including: scratch any itch.

This power might manifest in super stretchy arms. Or maybe a hand could detach itself and scurry after something. Or maybe I could levitate. If someone I cared about needed a hug, I would definitely teleport.

Yup. That's it. That's the power I want.