A person does not commit a transgression unless one is possessed by a spirit of foolishness. Therefore, each person – in precise correspondence to the transgressions one has committed and the spiritual blemishes one has caused – is literally insane. This is why most people have all sorts of quirks and idiosyncrasies. The rectification for this insanity is engaging in Torah study.
Based on Kitzur Likutei Moharan (Abridged Likutei Moharan) Vol. 1, Rebbe Nosson of Breslov, see I:1