Why Was Nerdism So Big in the 2010s Decade?

Why did everyone want to be a nerd back in the 2010s but also be trendy and cool at the same time? Hipsters were nerds, gamers were nerds, Comic book people were nerds, girls were even nerds, the guy with 1000 tattoo's all over his body was a nerd, etc...

What caused this? It felt like 99% of those people calling themselves nerds were not even nerds in the traditional sense, they just labeled themselves as nerds because it was trendy.

It seems to be getting made fun of again, and the term nerd is again offensive and an insult, those that used to call themselves nerds say they don't remember those days and don't remember calling themselves nerds, or that was another time and era, but I remember them.

What started it? What ended it?