日语中的彦语「人の噂も七十五日」中的「七十五日」是什么意思?

解释：
People have short memories.で「人の记忆力など大したことがない（すぐに忘れる）」の意味。goof-up「へま」、Gossip is short-lived.「噂ははかないものである」。

英语例句：
I wouldn't let a goof-up like that get to you. People have short memories, and the one good thing about gossip is that it's short-lived.

Don't let a little goof-up like that bother you. People have short memories, and gossip is short-lived.