Outcome goals run out of fuel
Most habits are built around an outcome: write the book, get fit, focus for four hours a day. Outcomes are useful for direction, but they are terrible fuel. They put the reward far in the future and quietly imply that every day before the finish line is a failure.
Identity works differently. Instead of "I want to write a book", the frame becomes "I am someone who writes most days". Now every single session is proof, not progress toward some distant judgement.
Every action is a vote
Think of each repetition as a small vote for the kind of person you are becoming. One focused session does not transform you, and it does not need to. It just adds one vote to the pile, and identity is decided by the majority, not by any single day.
This reframe also defuses perfectionism. A missed day is one vote against, not a referendum on your character. You do not need a clean streak, you need a clear majority over time.
Start from the smallest believable version
Identity change fails when the claim is too big to believe. Declaring "I am a deeply focused person" while you cannot sit still for ten minutes creates friction, because part of you knows it is not true yet.
Pick the smallest version you can actually believe today: "I am someone who does one focused block a day." Do it until it feels obvious, then let the identity expand on its own. Belief follows evidence, not the other way around.
Let the label do the deciding
Once an identity is in place, it quietly makes decisions for you. Someone who is "a person who focuses in the morning" does not renegotiate that choice every day; the question has already been answered, which saves an enormous amount of daily willpower.
That is the real payoff. You stop arguing with yourself about whether to do the thing, because doing it is simply what someone like you does.