Same, I find it much easier to start new projects, finishing them after I've done what I consider the core "thing" is much harder. We're clearly not alone. Not

Same, I find it much easier to start new projects, finishing them after I've done what I consider the core "thing" is much harder. We're clearly not alone. Not all projects are worth finishing, but I find that once the rush of learning new things have worn off and the only thing left to do is rigorous evaluation or polish my desire to work no it fades. I find tying some reason to finishing them usually gets me more willing to do so. Giving presentations about my work has often served as a good forcing function since they have due dates associated with them and the fear of being embarrassed by my work outweighs the boredom of doing the last ~20%. Not a panacea, but it helps me.