As a writer, I wrestle with these two ideas. A lot. I suppose everyone does in some aspect of their lives. It's like a constant catch-22 of wanting something but not wanting to do it. I hear running may be like that too but I wouldn't know. (snicker)
It's a constant ebb and flow. Things have to get done in life, right? Doctor's visits, groceries. So those are things you just do because you do, because you have to for living normally. Sometimes you do the normal things without really thinking about it and other times, you drag yourself kicking and screaming. Maybe you desire to eat so your discipline yourself to go to the grocery store.
With writing, I desire to tell a story. The stories just aren't as much fun roaming around in my head as when other people get to share in them. Stories are for sharing even though I immensely enjoy creating them in my head. So yes, I desire to get another book out to keep the inkling of writing career moving forward despite my day job.
But the application of the seat of the pant to the chair in order to type in a computer is another matter altogether. It is a discipline by all definitions. One must practice to improve and make progress! If I can muster the discipline to do it, I nearly always enjoy myself. I become lost in the story like I'm watching a movie.
Sometimes you hit a snag in the story and that makes it slower. Sitting and picking at it is the only way for me to unravel. This usually looks like me sitting at the computer scrolling, reading, and staring off into space.
I have seasons where I get in a grove and I walk in the house and sit down and write without thinking. Like some of those grocery runs that just occur without pain. But other times I like the idea of sitting to write but I don't get there without huge disciplinary effort of myself. I don't think books can get written on desire alone. I think all of them, if they are going to be good or decent, are going to require seasons of serious sitting, hammering, and red ink days.
It's the marriage of discipline and desire where things get produced out of love. There's another intersection where things get produced a lot too -- that is where discipline and the need to eat meet and we go to work for ourselves or someone else. Sometimes writing is in both those places.
One trick I use on myself when I'm resisting the big project, like I am now, is I promise myself just one hour. Only sit here for one hour and work on this, the promise goes, then you'll feel productive and get to do something else too. It works remarkably well for me. If you only do it one hour at a time though, you've got to do it regularly. Of course, the writing recommendation is to write every day. Sometime my life is like that and sometimes it isn't.
I heard a phrase and it's so true. I LOVE having written!