A habit is just a choice that stopped asking for permission.

At the start, everything is a decision, and deciding is tiring. After enough repetitions the deciding drops out and the behavior runs on its own, which is the whole point of a habit and also the whole danger. Good ones carry you on the days you have nothing. Bad ones keep running long after you would have said no if anyone had asked.

Notice one thing you did today without choosing it. Naming it out loud puts the permission step back in for a second, and that second is where any change starts.