Have you been robbing graves again?
My own questionable bruise was due to my spazzing or being overzealous while brushing my teeth - I poked myself in the back of my mouth, in the throat/uvula area. Didn’t think anything of it until I noticed an actual bruise there the next day, and foolishly mentioned it to my roommate. “Huh, I have a bruise in the back of my throat!”
She just smirked and cracked up.
Years ago I cut my wrist almost falling off a ladder, landing on some chimney flashing. Made a cut just like the standard Hollywood suicide image. I had to keep explaining how I got it when I noticed looks. The scar was quite visible for some time.
Now if your knees had permanent scars, then you’re talking.
When I lived in NYC, one of my exes once worked just off Central Park. He said his coworkers were wondering why he always returned from lunch with mud and grass on his knees.
(Actually, they didn’t have to wonder at all.)