I noticed myself repeating, "It's just my face!" often enough that I decided to make cards to save some time. I have what some call, "chronic bitch face" or "resting bitch face." I could be casually thinking about my next meal or what my cats are up to and get asked, "Are you okay/sad/mad/tired?" or told "You should smile more/cheer up!"
Most of the time the comments are pretty innocent and well intended (I'm definitely guilty of this too!). But here's my attempt at spreading awareness and shyly telling others to stop worrying about my face. :)