Your brain is always working to preserve your conscious attention for whatever task is most essential. Whenever possible, the conscious mind likes to pawn off tasks to the nonconscious mind to do automatically. This is precisely what happens when a habit is formed. Habits reduce cognitive load and free up mental capacity, so you can allocate your attention to other tasks. Read more in Chapter 3 of Atomic Habits. You can get your copy at atomichabits.com⁠ ⁠ #AtomicHabits