This has happen to me too many times to count. Usually on Sandy Blvd. I'm trying to make a left. I got my blinker on and I'm ready to go. I'm also quite ready to wait as there is a steady stream of cars.
There is always some guy who will stop for me and motion to go. What he never seems to get is that there is a steady stream of traffic to his right (my left).
I can see beyond him, the line of cars, all hauling ass in that very lane.
I motion for him to just go ahead and go. He get pissed at me for not taking him up his gesture. Never ever minding the potential t-bone that would occur.

I know I'm not alone in this. And it's always dudes.
Please stop.