Anyone can start the project. The last ten percent finds out who actually owns it.

Starting is enjoyable, socially rewarded and requires no follow-through. The end of a project is none of those things: it is detail work, loose ends and small unglamorous problems, with the excitement long gone. That final stretch is where responsibility becomes visible, because it cannot be done by enthusiasm.

When you notice yourself losing interest near the finish, treat that as the normal shape rather than a sign to move on. List the remaining items honestly and work through them. Finishing is a separate skill from starting and it is the rarer one.