While on the firing line at the range, what is the most off the wall excuse a Private has made up because they can't shoot?

I remember the urban legend of the MI Unit (admin, signal, who knows for sure), that zeroed every time, but couldn't hit the pop-ups. Answer was provided when one of the new NCOs to the unit caught a number of them using their weapon barrels as levers to fix their cots....

Once after coming back into service after a 3 year "vacation" I forgot that my combat zero was 27right and 3 up... About 60 rounds later at the zero line I remember... Only got sharp shooter that day but hey at least I remembered. Btw I do have a stigmatism in my right eye.