From This Might Be A Wiki

Possibly about dendritic spines (thus the neuron-sounding intro) in the emotional part of the brain (cry out of sadness, crawl out of nostalgia, beg and scream out of fear, and fall in love again).

The Spines might be about being tortured, and The Spines are the torturers. I don't know about the Fall In Love Again line, though.

The Spines are torturers, and the fall in love again line mean he's(narrator) released and caught again for loving someone he's not married to, and the Spines at the end of that part is the judge sentencing the guy to the Spines.-Professor Tor Coolguy

They are acctual spines, making you scream, cry, crawl, pay, with pain, then making you fall in love when they stop hurting, or is this like way too obvious? -Cody-schmidt

This song reinforces the idea that TMBG uses spines as a symbol for feeling and experience.

Great, now I get shivers down my spine every time I listen to Spines. -Jason DeLima 07:46, 31 January 2009 (UTC)

Waaaaay Literal[edit]

I think its about someone with a bad back, and it will make you cry, crawl, etc. Then you will fall in love with when you used to not have this back pain, something you once took for granted.