Are constantly at loggerheads.
Above my PC I have not one but 2 ideas for novels entirely mapped out in post it notes, scribblings, spider diagrams, the lot. In planning form, I've written two ACE novels. When it comes to writing the real thing however, the ol' attention span deficiency kicks in. It's like my brain says "Well I've thought of the idea, is that not enough?" and kinda gives up on me.
I've realised this alot through life. I'll throw myself into something 200%, care passionately about it, read up on it, learn things inside out, then when I reach a certain point, instantly give up and disregard it. I used to have a website a few years ago, doing flash animations, one being a really cheesy 'rap' about Chavs wearing Burberry. I set about making this website and learning how to use Flash because I thought "Some of the crap I see on telly started out life on the interwebs, I want a piece of this pie, cos if they've got that on TV, ANYONE can get it on TV." And lo and behold, I managed to get a few pieces on TV and the songs were used on radio (I actually went head to head with the BBC over Colin Murray using my 'Oliver The Humanzee' song that I made, repeatedly on his show and not acknowledging where he got it from or contacting me for permission first, I won and eventually got paid). Sky One, E4, Channel 4, I was even interviewed by someone from the New York Times about one of my animations about muppets who play their ringtones in public places, he mentioned it in his book about how people fight back against the little annoyances in life. And then once I'd achieved what I initially set out to do, I just gave up. Stopped. Kaput. I was getting emails every day telling me to make more, I was getting offers of freelance work, and I just gave up. The site died about a year later. And now I'm at the same point with writing. And I don't want to be, because I really like writing.
I blame blogs, I blame YouTube, I blame Facebook, I blame Wikipedia, I blame the internet as a whole. It sucks me in and I waste my time looking up stuff just for the sake of it. I'll be mid-sentence in a Word doc and then all of a sudden my brain will say "PIGEONS, you don't know enough about pigeons! Get looking them up!" 20 seconds later I'm looking at the pigeon varieties in the British Isles. I re-focus and get back to it. A paragraph or two later and lo, the voice chimes in again "PIRATES! What qualifications do you need to be a pirate? How do you start being a pirate? Is a boat necessary or can you be a land based pirate? Would being a land based pirate mean I have to restructure the pirate insult of 'Landlubber' to be derogatory towards sea-based people, 'Sealubber'? That sounds like Seal Clubber, hey LET'S ADOPT A SEAL!" It just spirals out of control!
Does anyone else suffer from this? Or am I just going slowly but surely mad and the novel writing is the carrot on a stick that I will never reach? How do I apply myself more to the cause at hand? I've tried severing my ties with the internet, I really have, but it's like a wicked wicked mistress. I'll disconnect my laptop from the wireless connection, 10 minutes later I'll be sweating and thinking "I wonder what's Kev's status is today? It said he hated Sealubbers yesterday...."

I had the same problem regarding writing a novel; had wanted to for years, but was always getting distracted from actually doing it. The internet is a massive distraction. I just had to force myself to keep off it while I was writing, apart from checking my emails, and if any came in that needed a lengthy response, they'd have to wait until late on a Friday night (that was my night off from writing).
You should definitely have a go at that novel(s). If I can discipline myself for a few months (and I am weak-willed, and have an addictive personality thrown in to further distract me), then I reckon you can too.
Mark
XXX