Why do I feel like I'm still wearing my hat?

We are now required to wear a hat for work. Which I hate because it’s too big. And wearing it backwards bugs my ears. But that’s not the question at hand. I took it off at 3:15PM. It’s now 6:26PM and I can still feel the area where it touched my head. It isn’t adjustable and there’s no elastic involved. It’s just a ball cap.

I have this happen whenever I wear hats, but not with other clothing. (Oh! Except my prom dress in 1982. There was elastic involved there.) It’s not a problem and should go away when I shower tonight. I’m wondering what this phenomenon is!