Majjhima Nikaya 4:51
SUJATOSo manasikaraṇīye dhamme pajānanto amanasikaraṇīye dhamme pajānanto ye dhammā na manasikaraṇīyā te dhamme na manasi karoti, ye dhammā manasikaraṇīyā te dhamme manasi karoti.
So they apply the mind to things they should and don’t apply the mind to things they shouldn’t.