>I was told I had no idea how viruses work (this is true enough - I don't have a degree in biology) but still felt extremely gaslit.

Similarly, on New Year's Eve 2015 I saw mention of the Cologne mass attacks on women by refugees as they were occurring on, yes, 4chan/pol/, and checked /r/worldnews and /r/europe to find out more. I didn't see anything, and assumed that it was another /pol/ "it's happening" dank maymayism. I only later realized that German media and those subreddits' mods had all worked to suppress news of the attacks until they could no longer be ignored.

(Cue "/pol/ was right" couplet)