No wonder it was in the 75% off bin...

Nearly 30 years ago, at a music convention, I bought a book of musical staff paper.  I thought it would be fun to compose my own music.  After I bought it, however, I took a closer look and realized I'd have to eliminate the top or bottom notes from any composition I planned to write.  All of the staffs contained four, instead of the standard five, lines.  That was one of my earliest cases of buyer's remorse.