I was like 18 and on my way to my doctor's office driving through a residential area. I was behind some guy at a light waiting to turn left. Light turned green and I gave it a few beats... One... Two... Three... And I lightly beeped my horn. He was clearly too deep in discussion to pay attention to driving, but it did the job, off we go. 

He was being a dick the entire time I was behind him, driving far below the speed limit and weaving all over the road to show me I was at the mercy of his driving. So when he went straight through at a stop sign and I turned right, I give him a second little honk as a fuck you.

Fucker turned around and FOLLOWED ME to my docs office, proceeded to get our of his car when I parked and verbally berate me for honking at him while his trashy girlfriend/wife yelled at me from the car. Not creepy and fucking insane at all. And all cause I honked my fucking horn.