When was the last time you did nothing but code all weekend? Have you ever started coding on Friday night and not slept till early sunday morning?
I program all day every day!
My day job is as a programmer, although it's very different to the stuff I do as a hobby. For a job I write telemetry analysis stuff and am mostly php based, but my passion is making stuff in 3D. So at some point mid-late afternoon I switch from doing trajectories to vertices :)
The trick to finishing a project is to stop having new ideas, or if you do, to save them for a future version. Stick to the game plan!