Do you have a good 'excuse'?

Ie. were you flying full time (or working your way through school) and going to school full time? My grades were not good, but I don't ever recall anyone at Delta asking me about it. But prior to Delta, when I was being interviewed for an Air Guard slot, they did ask me why. My 'excuse' was, I was flying cancelled checks all night, M-F, during my last two years of college.