Know what you mean Jake, but enough people have said train your brain to a schedule that I think there must be something to it. Does not work for exercise though. Daydreaming instead of lifting, running or cycling just leads to more daydreaming...
My advice to anyone with writerly ambitions and a demanding day job is to set aside a little piece of time, even an hour a week if that's all you can manage, and make it yours. This is your writing hour. Even if you use it up by staring at a...