I'm a stupid man.

One hour ago, I drove a car of a company and went to a convenience store. I bought a lunch box and Japanese tea for lunch. When I returned to the car, a uncle man/guy who I didn't know sat down at the passenger seat of the car. We were looking at each other reciprocally for about 10 seconds and then he said: "Why do you sit down on my car selfishly?" I got out of the car though I think it's somewhat strange (weird). I saw a car with the same color and type as mine. It's the 3rd time that I took the wrong car.