My Dad had several memorable phrases that you hardly ever hear these days, and even back then they would probably be viewed as fairly antiquated.
One of his favourites was to tell me I was ‘hoist by your own petard’. I never really knew what it meant, except that I was kind of the victim of my own devious plan.
Apparently, according to the good folks at wikipedia, the actual phrase is ‘hoist with his own petard’, from Bill Shakespeare’s Hamlet. It means to be blown up by your own bomb, petard being the bomb part. It has, or had, come to be used proverbially, when something to you try to do to bite someone ends up biting you back.
Fantastic! It came to me the other day, though I can’t remember how my brain accessed it. I do need to start getting it into everyday conversation, if at all possible.