Something weird happened at the park

I was parked in the parking lot staring at the water. This man in what looks like his 60s parks next to me in an older blue Buick. Whatever. Well I looked over and hes making the hand motion of trying to get me to roll my window down. I refuse. He keeps doing it and at this point I'm going to leave. As I'm putting my car into reverse to leave he honks at me. I dont even know the guy. I drove as fast as I could home.