The most difficult thing about writing is actually doing it -- sitting down every day to pound out some sentences. Once you get on a roll, it's not half bad, but getting moving can be painful. Staring at the screen, re-reading what you wrote yesterday, checking out your fingernails, counting the cracks in the ceiling....so much to do!
When you finally get going and into that world you have created from whole cloth, it can be drug-like. Time will expire and you will be oblivious to the physical world. You will feel that you know these people you have created. Non-writers don't understand how you can write all day and not crave the company of other people. They don't understand that you have been with people all day long, moving them about, letting them yap on and on, feeling their fears, joys, nervousness, and passion. It can be exhausting and you can feel at the end of a writing session that you just want to be alone! Alone with your own thoughts!
Ah, but getting to that place is the rub, as Shakespeare would say. Sitting yourself down, concentrating on what you are about to do, channeling that other world and those other people, snuggling into their skin, getting lost in there . . . in those pages of type you are producing. Some days it simply doesn't happen. Some days you slip right in without a backward glance.
But most days you have to force it. You have to pry open that world with a dull spoon and writhe and wriggle into it, a stranger in a strange land -- at least for a few paragraphs or a few pages -- searching for the familiar, for that spark that will set fire to the kindling of your imagination.