What are the things that would piss you off if you didn't get your fantasy career?
Not much, really. I think I would tend to be regretful about not every fulfilling the dream. Since I'm giving up regret, though, we don't want that. So more work on the dream.
I think I'd be angry about having to go to "the office" everyday if I didn't become a writer. By that, I mean, going to somewhere that I am expected to be at certain times even if there is no work to do. I am goal and task motivated and believe that increased efficiency means I get to go home earlier. It does piss me off that I'm expected to do dumb-ass busy-work or pointless "training exercises" just because I've been efficient in getting my work done or there isn't work to do for some other reason.
So I'll channel that anger into energy for writing. Every time I get pissed at some idiotic thing at work, I'll put in time later that day writing. Sounds like a plan.