What do I mean when I say "humans!"

Or perhaps "because humans"? Conversation with metahacker resulted in me trying to figure this out. :)

I think there's a certain amount of 'this thing that someone/a group of people is doing or has done confuses me immensely and thus I feel like an alien.' Probably see 'autism spectrum', I R on it, here.

Also, some 'this thing bothers me and it comes up too often for me to put any brain space into it right now.' Usually sexism, I think.

I don't think I use it to suggest that this is a thing that people - all people - do and I just need to accept that. I am aware that other people do use it this way!

I may use 'because cat' in that kind of way, though. Hmm... even that may be more of a case of "this is a thing that only makes sense because you are a cat", rather than "and every cat does this thing that you are doing right now".

Do any of you use a phrase something like this? And if so, what do you mean by it?