Focus is the ability to stay after novelty leaves.

The first stretch of any project is carried by novelty, which is free and does not last. What determines outcomes is what happens afterward, in the long middle where the thing is familiar and unglamorous and still incomplete. Focus is mostly the capacity to remain there.

Notice where your attention typically fails: usually right after the initial excitement fades. Plan for that point specifically, with structure rather than enthusiasm. Getting through the middle is the whole game.