@NotMeNotYou: That's what I figured it was, but I can't figure out how to open my mouse, and none of the videos show my specific mouse since I have a weird variant.

I've even scraped off my Teflon tape and found literally zero screws.

@zenitix: It might be glued shut then, which means you need a new mouse to fix it. Microsoft makes some good laptop mice that fold down, if you'd like a comfortably large one that won't take away too much space in the bag.