I think when you start off any piece of work it is because you have been moved in some way, maybe by some little thing, like in POTIKI. When I began that it was because I looked into a room and I saw a man there bending over a carving and making something.
If my doctor told me I had only six minutes to live, I wouldn't brood. I'd type a little faster.
Writing is easy: All you do is sit staring at a blank sheet of paper until drops of blood form on your forehead.
It is necessary to write, if the days are not to slip emptily by. How else, indeed, to clap the net over the butterfly of the moment? For the moment passes, it is forgotten; the mood is gone; life itself is gone. That is where the writer scores over his fellows: he catches the changes of his mind on the hop.
In summary, don't let your writing days slip past by not writing. Find a way to make a start - write about something that moves you, write like there is no tomorrow and keep writing, even if the going is tough at times.