They disregard social conventions without being conscious that they are doing anything extraordinary.
请问这句话中的anything能被Something替代吗？
something用于一定句，anything用于否定句，所以大家说：
They are not doing anything extraordinary.
They are doing something extraordinary.
假如他们正在做不同一般的事情，但自己却没意识到这一点，大家用主从复合句，主句为否定句，但从句却是一定句：
They are not aware that they are doing something extraordinary.
假如他们没做不同一般的事情，他们也意识到这一点，大家用主从复合句，主句为一定句，从句为否定句：
They are aware that they are not doing anything extraordinary.
类似的例子还有：
He doesnt know he has made some mistakes.
He knows he hasnt made any mistakes.
本句中，主句They disregard social conventions 暗示他们正在某些不符合social conventions的事情，所以that从句应该是一定句。我觉得，本句中的anything不但可以改为something，而且改用something更符合整个句子的语境。
that从句用一定词还是非一定词，不是取决于they是不是意识到他们做还是没做某事，而是取决于说话人觉得他们做了还是未做某事。而句首的they disregard soical conrentions 强烈暗示他们正在做某事，只不过他们没意识到而已。that从句是个一定句，应该用一定词something, 而不是非一定词anything。