The cue is time, place, state, or the previous action: 16:00, monitor, fatigue. The action is tea with a cookie. The reward is sugar, a break, the feeling «I deserved it». The brain remembers the connection and starts the action when the cue appears, even before you notice. Any link can be changed, but the easiest are the cue (remove the cookies from sight) or the action while keeping the same reward (a tea break and a walk). Banning the action while leaving the cue and reward means fighting your brain every day. Analysis — habit loop.