You can’t download a new habit while your storage is full of old ones. Delete something first.

A new habit needs the time and attention an old one is already using. Adding without removing means the two compete, and the established one wins because it has years of practice behind it. Most failed changes are not a shortage of motivation, they are a shortage of room.

Before you start the new thing, identify what it is replacing and be specific about the slot. The half hour after dinner, the first thing on waking. Take something out deliberately so the new one is not fighting for a place.