I'm Still Not Used to People Assuming I'm Stupid...

[apple_pathways]

A customer comes in wearing a t-shirt with the Greek letter π surrounded by a spiral of about 100 of the known digits of the mathematical constant. It starts on the outside with 3.1415926... (etc.) and then spirals inwards to where it fades away.

Me: I like your t-shirt!

Customer: Oh! Yes, that's 'pi'.

Me: (stunned silence) I...know. I'm a math tutor.