Crazy guy

Holy shit. I just discovered that there are some fucking CRAZY people in this world. Like, literally fucking crazy. I was riding my bicycle back home after class this evening and, at an intersection, as I was going west on Harbord, I got off my bicycle at Spadina to walk through the pedestrians crossing north and south across Harbord, so I could remount and start riding north up Spadina (just past the pedestrian zone). It's hard to explain, but anyway, I CERTAINLY didn't do anything to warrant this fucking madness. This guy walks past from behind me and seems to be mumbling something angrily, and I realise that it's directed to me. And this happened:

Him: "[barely-heard initial angry grumbling]"
Me: "sorry"
Him: "Next time I'm gonna kick your fuckin bike out the way, buddy"
Me: "I'm sorry.."
Him: "Yeah you will be sorry!"

What the FUCK? Is this a practical joke? I don't get it. He literally acted like I ran over his first-born daughter. Holy shit. I thought he was going to kill me or something, and it was all just because apparently, while walking past, I cut him off and thus delayed his travel by like fucking half a second. And he was an adult, a fairly respectable, normal looking character, too, not a crazy teenager or something.
Anyway I'm completely unable to fathom how someone could get SO angry at such small shit. Like, how is this guy not in jail? I mean, I can't imagine how he'd react if someone was ACTUALLY rude to him or whatever.

As soon as he was sufficiently out of hearing range I was standing there still and people who were standing there around me, waiting for the light to change, were staring at him and shit, and i said "holy shit.. wow." and then took off. which is really bizarre for me because i said it loud enough that those around me could hear, and usually i'd be way too shy or whatever to say anything 'publicly' like that but it just came out, and i liked to think that the surrounding people were on my side.