when you father was an engineering student, and you are in a private high school and playing guitar in the music band, if you are not a talented a carrot in god's potato field, you have done diddly-squat with your private education.
"Boo Diddly Squat" is my second Sheryl Crow's "Soak Up The Sun" joke. "Boo Diddly," is a Super Mario Bros. series, ghost enemy. "Soak Up The Sun," mentions her job, "doesn't pay diddly squat," meaning it doesn't pay her enough. In this case, Sheryl Crow, in the Mario's Mushroom Kingdom, is angry, that Boo Diddly's doesn't get paid, for working for Koopa Bowser! A joke!
Sheryl Crow, is angry, that a Koopa Bowser minion, a ghost, is paid "Boo Diddly Squat" despite being, a great employee, of this boss! A joke!