Y'know, there's a saying -- if one person's an asshole, it's probably them. if everyone's an asshole, it's probably you
And nice way to avoid the main point of a comment once again.
Does it really matter where the saying comes from? I assure you it's quite common in the US in the "regular" people circles you claim to be so familiar with. The meaning has nothing to do with you or calling people assholes -- it simply means that if you have a problem with lots of people (as opposed to one person) that the problem may lie with you rather than the other people. But you really didn't need that explained, did you? Maybe we can eventually make language a complete impediment to understanding. -Hobbes