The cumulative effect of recoil is indeed 'all in your head' (and cervical & upper thoracic spine, shoulders, and vestibular system) and it's called repetitive traumatic brain injury
http://www.cdc.gov/ncipc/factsheets/tbi.htm http://www.ninds.nih.gov/disorders/tbi/tbi.htmMuhammad Ali, lots of former NHL players,
and soldiers are examples of the result. And those with previous traumatic brain injury are much more sensitive to additional trauma. Being 'afraid of the recoil' is
not the problem experienced shooters are fighting.