Tell them your wife cut you, because you saved a woman from drowning. When they ask what river was the woman drowning in, tell 'em it was your bathtub.
The silliest way I cut myself, not counting the times when it all started with a phrase "hey, look what I can do." Would be almost slicing of my middle finger with a leatherman wave while trying to separate two beads on the bead door thingy that were stuck together with clear coat. Lesson don't hold your hand in the path of a blade when the only thing stopping it from going there are two things stuck together, which you are just happen to be attempting to separate.
My old man came home one day a little drunk and with three condoms on his three figures. He was a biochemical process automation engineer, and they were designing some piece of equipment that worked like a press. Long story short, that press took out my father's finger tips, so the helpful coworkers gave him a drink, this was a while back and I don't remember all the details, but the condoms were part of the materials used to dress the wounds. Now his three fingers are equal length and don't feel as much.
And Jack you think your doc was mean, my parents told me to "walk it off" or "sleep it off" no matter what, 5 trips to the emergency room later they are still reluctant to admit their advise was wrong. When I broke my pinkie playing basketball or volleyball, and told my mom I should see a doc about this, she asked me to show her the finger, then when I did, she suddenly pulled on it, and moved fast side to side. When the shook passed and I was finally able to make a sound, I asked why did she do it and she said something like "If it was truly broken, it would have hurt so much that you would have screamed and maybe passed out from pain, but since you didn't do either you must have just pulled a muscle or something." My pinkie is still can completely open up, and they are telling me it was like that since I was born. The worst part is I guess my parents took me for a wimp, and if I didn't scream or didn't pass out then it didn't require their attention (except for two times when I've done something really incredibly stupid/dangerous, and was afraid I'd get my @$$ handed to me just for what I was doing when I got badly hurt.)