Hair as the seat of strength has scriptural authority: Samson's power lived in his unshorn hair, the mark of his Nazirite vow, and left him on Delilah's floor with the barber's work. The motif is far wider than Israel, since hair, growing from the head, visible, and surviving the body, collected beliefs everywhere, the warrior's uncut locks, the widow's shorn head, the relic lock kept in the family Bible. Cutting has been consecration, mourning, punishment and enslavement by turns, and the old dream handbooks read hair accordingly: abundant hair toward strength and standing, hair lost or shorn toward loss, disgrace and grief.
Psychoanalysis translated the old readings into its own tongue, taking the cutting of hair in dreams as one of its standing images of castration, potency lost, a reading that belongs to that theory and is recorded as such. The gentler modern line reads hair as identity's most workable material, the part of the self that is groomed, displayed, coloured and cut by choice, so that dream hair falling out unbidden is read toward control slipping, and a deliberate dream haircut toward change undertaken.
The folk registers persist underneath, grey hair toward wisdom or worry, combing toward setting affairs in order, and the dreamer's own waking relation to their hair, vanity, covering, faith or loss, is the context every school consults first.