For me I think it sometimes has to do with not feeling confident about how my hair looks. I do it a lot less if I feel that my hair looks great. Unfortunately those days are few and far between.
2b/c wavy modified CG since July 2012
medium texture, normal porosity, normal elasticity
hair likes protein, doesn't like oils, easily OC'd
low poo: JCHCC, CJGCS
RO/co-wash/LI: YTCarrots, DB Pumpkin Seed
stylers: a bunch of stylers that are all pretty much the same (KCCC, UFDCM, CRCM, CKCJ) or ArcAngel if I need more hold
DT/PT: CJRM, CNPF