Dumb drivers

I just needed a place to rant, but I was driving in a parking lot and you'd think any car going straight has the right of way unless specifically told so. Well, this old dude in a Mercedes decided to turn left directly in front of me when I had no stop sign or anything anywhere in sight when was driving straight slamming on his brakes. Then proceeded to get out of his car to scream at me saying he had the right of way.