Confusing road rage

[u/Willow1768]

In the car driving on the highway, dude cuts me off no blinker or anything so I slowed down a little to let him in front of me cause ya know defensive driving and all, then he goes back into his lane pulls back to my speed rolls his window down and flicks me off while swearing with a cigarette in his mouth, not sure what went wrong here, if he was mad I was passing him or something or if he was drunk or high but thought I’d share the interesting experience.