Like when you try to save some money on a tune up and, in the process of doing it yourself, break your distributor body and, in the process of putting in a new distributor got the timing all out of place so the car won't run and breaks down twenty miles from home
in the middle of the night. In that instance you would tell the towtruck driver "Well, I guess I fubar'd that damn thing (At least
that's what I told my tow
truck driver when I did it).