Lyric discussion by Eccentricity 

Cover art for You Were Cool lyrics by Mountain Goats, The

As to the spiked heels thing, for a hint to one possible interpretation: Gender is not specified in this song.

He does mention in one of the live recordings that it was about a girl he knew in high school - and that we know her from another track of his (but we don't get to know which one).

Probably the girl he dates in "Broom People."

Probably Cathy. Possibly Jenny but I think she is fictional.