A guitar doesn’t stay in tune because you tuned it yesterday. Neither do habits.

Nothing stays tuned on its own. A guitar drifts because strings stretch and wood moves with the weather; the tuning was never a permanent state, only a setting you keep returning to. Habits behave the same way, which is why slipping does not mean you never had it. Upkeep is the normal condition rather than evidence of failure.

Build in a short check instead of waiting until something is badly out. A Sunday look at the week ahead, a quick count of what you managed, one adjustment. Retuning often is easier than retuning rarely.