Don't worry about it. We've all made that same mistake many a time. = Many's the time we have made that same mistake.别担心。我们都曾多次犯过相同的错误。We've been there many a time.我们已到过那儿多次。We've been here many a time.我们这儿已来过多次。I've been there many a time. 我已经到过那儿很多次了。I've told you many a time not to ride your bike on the pavement.我告诉过你很多次了，不要在人行道上骑自行车。