The track was written by Dominique Durand, Adam Schlesinger and Andy Chase while production was handled by the latter two and Peter Nashel.

Released alongside "This Is the Day", "You Don't Know Anything" received promotion by Atlantic Records after the former track was included on the soundtrack for the 1998 film, There's Something About Mary.

The recording received generally favorable reviews from music critics who compared the song to the works of Irish rock group My Bloody Valentine.

[1] The single was heavily compared to My Bloody Valentine; in their review of the track, Sputnikmusic stated that it "comes off like a My Bloody Valentine song with intelligible vocals, with a sliding, reverb heavy hook and pummeling drums",[2] while AllMusic writer Jack Rabid drew similar comparisons.

[1] Patrick Carmosino of Consumable Online stated that with "You Don't Know Anything", Ivy "have an indie-ethic rock side that compliments their pop sensibilities to the tee".