The mind unlearns with difficulty what it has long learned.

Old learning does not get deleted; new learning is layered over it, and under pressure the old layer surfaces. That is why habits you thought were gone reappear when you are tired, and why changing a long-held way of doing something takes more repetitions than acquiring it did. Knowing this spares you from concluding you have failed every time the old pattern shows up.

Plan for the old pattern returning as well as for keeping it away. Decide now what you will do if it reappears, so that a slip becomes a cue to use the plan rather than proof that nothing has changed.