What Is This Supposed to Mean?

The comedian Lewis Black has a great bit in which he describes the aneurysm-inducing experience he endured after overhearing a young woman relate an utterly incomprehensible story:

“Behind me, I heard a young woman of 25 say, ‘If it weren’t for my horse, I wouldn’t have spent that year in college,’” Black recalled. “Now, I’m gonna repeat that, because it bears repeating: ‘If it weren’t for my horse’ — as in, giddyup, giddyup, let’s go — ‘I wouldn’t have spent that year in college,’ which is a degree-granting institution.”