I find that often even my most random dreams can be tied to something that occurred during the day. I normally don't tell stories about my dreams, because no one really finds them that interesting; they just listen politely so they can tell you about the crazy dream they had recently. But it's my blog, and I'll bore if I want to.
So in my dream last night, a friend of mine had a pet rattlesnake. We were playing with it (because what else do you do with a pet rattlesnake?) and it bit me on the side. It only barely grazed the skin, so it wasn't a big deal. Then it bit me on the arm, nice and deep. It was a big deal, and yet dream-me didn't seek medical advice. Because apparently pet rattlesnake venom won't kill you like wild rattlesnake venom.
I woke up thinking how weird it was that I was being bit by rattlesnakes in my dreams, and then I realized that the arm that got "bit" happens to have a large bruise in that spot, thanks to a poorly performed needle stick (I told them not to use the right arm!). I must have been putting pressure on the bruise in my sleep--heaven knows it doesn't take much to make me wince.
So there you have it--bad needle-caused bruise yields rattlesnake bite dreams.