My father is an engineer, and he always taught me that there's no such thing as a good job half completed. The problem with his perspective is that it is uni-dimensional, and with good reason: if you half-build a bridge, people are going to be sad. He's an engineer and he's got to finish the bridge.
However, my father didn't decide that a bridge was required, nor did he choose the ideal location for the bridge based on urban planning and geographic surveys. And let's be clear — he's not going to be out in the rain, assembling raw materials into a structure either. His job would start with the design and continue with the project plan, and possibly end as a consultant or one of a team of over-seers. He's not finishing the bridge, but his role was necessary to get the project from where it was to where it needed to be when someone else would take over.
Technical projects are often the same. I'm generalizing, but you see a lot of supporting evidence which suggests that you have your visionary, your architect, your builder and your "last 10%"-ers. One person can be all of these things, but almost never all at once on the same project.
What I learned when I came of age was that I am a Starter. I have good ideas and the ability to rally others to a cause. I've evolved the ability to network and communicate. I've forgiven myself for not being a Finisher, because there are lots of people that hate starting and love to finish. There are loads of people who will never start and hate finishing, but they are the core team during the middle.
I suggest that you stop seeing your inclinations as a problem and start thanking your lucky stars that you have a regular flow of potentially great ideas. The main skill you need to develop is your ability to kill off the bad ones early so that you can focus your passion and evangelism on the winners.
Chances are, if you got bored it wasn't going to turn out well anyhow. Listen to what your subconscious is trying to tell you.
http://www.humblepied.com/jessica-hische/