The song has only three lines:
Verse: "Won't you believe it; it's just my luck."
Chorus: "No recess."
Post-solo: "You're in high school again."
Kurt Cobain wrote this song after feeling a crushing disillusionment with the smallness of the Seattle music scene that he had such high hopes for, migrating to it as a refugee from his cruel rural abyss.
It could be a song of disillusionment, really, with any job environment.
And then you realize this entire country is basically stuck in high school, at best.
And it hits you there is, indeed, no break from this - no recess.
The album version of "School" is great, but nothing really compares to the live attack, with Dave Grohl providing a savage wall of sound that the album drummer Chad Channing could never conjure.
Nirvana proves that songwriting can be very low-maintenance: If you have the talent, you can work with very little. Verse guitar riff: One string, two notes. Chorus: Four chords. All that is required is a gift for optimal configuration of those elements for melodic possibility and dramatic power, but that's where inspiration is required.
You don't get a hall pass for inspiration.