You really notice this if you're outside mainstream social networks. People at some point start to have infinite discussions IRL about some new uninteresting topic you never heard about like it was the most important thing in the world.

You listen them argue with polarized and surprisingly well defined opinions, like they're reciting some script they're supposed to follow to defend their faction of choice. You change social circle, like go from friends to family, to find the very same discussions with the same factions and the same detailed, almost scripted arguments.

Meanwhile you keep wondering why they even care, and why they're so passionate about it, it's like they're under some kind of spell which for some reason didn't work on you.