Playing doctor

We were in moms closet the other day looking for treasure (mom gets really exited when we hunt in there!) and we came across this strange looking cap.
Morty said it was obviously part of a funny halloween costume but i think he's wrong, as usual. The last time i saw a cap like this i was at the hospital and the doctors were wearing them on their head and feets.

WAIT a minute!! Is mom secretly a doctor?! Or was she playing doctor? And if she wasn't playing doctor with me or morty, then who?!!!!

Alright, I know I ask a lot of questions but this "cap" is just making my mind reel! Mom, stop laughing uncontrollably and tell me the truth, I can handle it!