Was getting gas late one night, there were a few more cars at the station. As usual for our town, there is always at least one crackhead wandering between the gas stations... begging, trying to sell whatever they stole that day... etc. I've always been good about keeping my head on a swivel and knowing where people were... but the guy that approached me was literally so skinny and black, view of him was obstructed by the pump until he was just on the other side of it, nearly within arms reach of me.
I had my back turned to him at the time, just about to take the nozzle out of my car when he says something and holds his hand out towards me. I later realized he was trying to show me something, probably in an attempt to sell me something... but point is, you don't sneak up on someone pumping gas at 1:00 am, and wait until you're at arms reach to announce yourself.
I didn't draw immediately, but he startled me pretty well. In one motion I spun around, took a step back, and had my hand on my gun before I myself even realized what happened. Needless to say that was all it took for him to change his mind and get the hell out of dodge.