4chan, in part, ruined real life. So much of the initial meme buzz around Trump came directly from 4chan - god emperor, etc. /b/ and /pol/ had large coordinated campaigns to boost Trump for lulz and to fuck with people. These made the news occasionally and were sometimes quite wide-reaching. Edit: not to forget Qanon, pizzagate, etc.
Additionally, 4chan is responsible for a massive swathe of meme culture more broadly. Most people don't dredge its depths or even know "the hacker named 4chan" exists, but it has been a massively influential force.
In home ec class in middle school we watched a food network video about making stuffed hotdogs where they took a straw and cored a hotdog out and then filled it with white, melted cheese from a piping bag. They squeezed too hard and it jetted out the other end and the camera was perfectly positioned to catch the hotdog's thick ropes. Then they played it back in slo motion. The class was very amused.