Why are people, especially old people, so mean?

I saw an old guy yell at a cashier last week, I told the cashier I was sorry for her after he left, but he was too scary to confront directly. Today I was yelled at by an old lady sitting next to me when I asked her to put on headphones instead of blasting her phone. A few weeks ago I was I'm crossing the street in the cross walk a middle aged couple almost run me over and them flip me off as I cross.

Every time something like this happens I want to cry, today I did cry when that lady yelled at me.

I feel like everyone hates everyone else and I can't stand it anymore, it just makes me sad. I don't remember people being this mean when I was a kid.