Conversational gem with my mom

Mom and I have been getting in a lot of fights lately over how I lose things. This is one of them.

(I'm reading in the living room when Mom comes in.)
Mom: I found your toothbrush.
Me: What? It's not missing.
Mom: It's in my bathroom.
Me: That doesn't make sense. I haven't been in your bathroom all day.
Mom: Go get it.
(I give her the benefit of the doubt and go get it.)
Me: Look, it's not my toothbrush. Mine is in my bathroom upstairs.
Mom: I can tell it's yours. The bristles are worn down on the sides.
Me: But my toothbrush is upstairs.
Mom: You're probably hurting your gums. Look how worn down it is on the edges.
Me: It's not mine.
Mom: Your toothbrush shouldn't look like this.
Me: IT DOESN'T! IT'S NOT MY TOOTHBRUSH!

I have no idea who owns that toothbrush. It's still in the living room. I feel like we ought to all swap our cheeks and find a match in my mom's lab.