don’t blow it (before the fact) or you blew it (after the fact) are expressions that indicate failing to take advantage of an opportunity.
i was really jazzed to find this clip from copland on youtube. it is always the first example of you blew it that comes to mind when it comes up in class. sylvester stallone is a cop in a small town in new jersey, and robert deniro is an internal affairs cop for the nypd who asks stallone for info about corrupt activity by new york city cops who live in his town. stallone is slow to provide the information.
will ferrell exploring the studio space
at this link you can see one of my favorite saturday night live sketches: a mockumentary about music producer bruce dickinson (christopher walken) recording the blue oyster cult song don’t fear the reaper. the band has some creative differences, and around 3:45 in the video one of them shouts “don’t blow this for us, gene” at the cowbell player (will ferrell)
don’t fear the reaper
don’t fear the reaper refers to the grim reaper: the image of death that comes to collect the soul of a human who is about to die.