I hear lots of blatantly false laughs all the time, usually combined with plenty of equally obvious signs that the person can't be bothered to actually listen much at all to what they're being told. The fake laughter is just one element of their well-supplied repertoire of fully generic replies which require no thinking or comprehension, and which also make you look like the bad guy, or like you're crazy, if you show any signs of discomfort or indignation. I think the blatant fakeness signals to neurotypicals that they just have to put up with it, or else they'll only be asking for trouble, and they accordingly behave as if they couldn't detect it at all.
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The red lake has been forgotten. A dust devil stuns you long enough to shroud forever those last shards of wisdom. The breeze rocking this forlorn wasteland whispers in your ears, “Não resta mais que uma sombra”.