Spine-tingle, mind boggles
In the central nervous system (which is composed of the spine and the brain), the spine is known for automatic reactions. Reactions that need processing go to the brain. Thus, Ghostface is saying in the line before that he throws knives in Chicago, which stays windy (meaning he uses knives as a weapon and throws them aimlessly). But it’s an automatic reaction (the spine tingles), and he only thinks about it afterwards (mind-boggles). Kinda like a ‘shoot-first, ask questions later’ type of thing.
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