If you remember the game Lemmings, you'll remember the brick-laying lemmings that could build a fragile span, brick by brick, stretching from the starting point to some far distant goal. That how I feel about first drafts. I don't start writing until I have a beginning (obviously) and an ending and a couple of definite points in between, but then I have to construct that thread of a bridge from one point to another.
Some people seem to enjoy their first drafts and can write to explore, but mine seem very precarious. I mustn't look down and see how far up I've come. Eeek! No, that brings on vertigo and feelings of panic. Can I keep track of everything? Will it make sense? And I mustn't look back and start admiring what I've written so far. That also leads to a complete fear of forward movement as I become sure that what I'm about to write can't be anything like as good as what I've already written. Yes, it wasn't bad, but that must have been a fluke, right? (That of course is on the days when it does look good and not on one of the days when, unaccountably, the whole MS has turned into a pile of stinking doo-doo when I wasn't looking.)
I've also, finally, learnt that I musn't let anyone read or critique a first draft. This conflicts rather with the desire to share the story with someone as soon as possible, but again, rather counter-intuitively, someone saying, "Wow! That was great, can I have more please?" puts too much pressure on me to perform and I can slide into, if not writer's block, then certainly writer's lethergy and production goes right down.
So like someone climbing a cliff, I have to focus on the bit right in front of my eyes, whilst occasionally glancing ahead to make sure I'm going in the right direction and occasionally glancing back (being very careful not to look too hard at it) to check stuff to keep the story straight.
25% done so far. Only another 75,000 words to go.
Did I ever mention that I hate first drafts?