Like the more well-known saying, "to be on the bandwagon", but it is used when one likes a band before they become cool.
Steve: "I see a lot of little kids like Green Day these days."
Mark: "Yeah, they're all jumping on the Green Day bandwagon now. But us two, we were on the band shortbus. We got "39/Smooth" when it first came out."
When typed into a calculator and flipped upside-down, it reads "BIgBOOBS"
That babe I sit next to in Algebra, she got (typed in calculator)58008618!