Oh my gosh! That's another pet peeve of mine! That's happened to me a few times too. Even driving, same thing. I have some space between the car ahead of me. Inevitably, someone will try to squeeze in front of me. It's nuts! All the room in the world behind me, or to the side, but that little space in front of me looks better. Bugs me. And 9 times out of 10 it's not even a turn thing.
I had one looney tune whip around me real quick to get in front of me the other day. There was a back up at a stop light and it went to an intersection that crossed into a neighborhood. I didn't block it. There was no where to go anyway. There were a few cars that turned through it. While the light was still red and no where to go still, this whiz behind me, got impatient that there was space in front of me, so he pulled out and around me, blocking the passage.

One of the few times I laid on the horn for a real long time. Once the light changed he changed lanes and zoomed off. I guess he wanted to get away from the crazy horn blower.
Driving anywhere can be a trip in more ways than one.