My neighborhood has a lot of what I call Street Cats. These are cats that grew up on the street and lived off of food left out by well-meaning residents and the huge wild bird population. Usually, when I pass by on my walk home from work, the cats run away before I even get near them. This one cat I passed, however, seemed perfectly fine with my presence. I figured that he/she/they(I didn't check)was more tame than the other cats and would probably be friendly. Indeed, when I said a few gentle words and put out my hand, he rubbed his head against my hand...
And then gave me a gentle bite (no skin was broken in the telling of this tale).
I recoiled and figured I had touched the cat in a place it didn't like. I've had that happen before with completely tame cats. I, thus, attempted contact again. I approached the cat, put my hand out, and the cat generously allowed me to touch him for a split second before brushing it's teeth against mine once more (again, no skin was broken).I felt stupid for trusting the cat for a single moment, and now know how Sakaki from Azumanga feels.
Moral of the story: Don't trust strange cats to be friendly. I know that I should know this by now, but there you go.