The phone is an environment, and environment shapes behavior. When the device stays in the bag, the habit of checking it weakens, because the cue disappears. When the device is in the hand, the habit strengthens, because every lull invites a glance and every glance invites another. Most schools already restrict phones, but the guidance now pushes for an all-day standard, including breaks and lunch, so the social reward loop is interrupted as well. Students will adapt to whatever is enforced consistently, and they will exploit any loophole left open. Can adults tolerate the first noisy week long enough for the new norm to settle?