'A square peg in a round hole is a no go.'No good deed goes unpunishedThis means that life is unfair and people can do or try to do good things and still end up in a lot of trouble.No great shakesIf someone is no great shakes at something, they are not very good at it.No harm, no foulThere is no problem when no harm or damage is done, such as the time my sister-in-law stole the name we would chosen for