Why is a bicycle like a writing desk?

[lizvogel]

This is now my new way of explaining why I can't work out a plot beforehand, courtesy of this Pat Wrede post about prewriting:

"Furthermore, writing is, in some ways, like riding a bicycle—a lot of things don’t work right/aren’t clear until one is moving forward."

This is me, with plot. No matter how much I'd like to fill in that gap between M and Q before I start writing, I've got to get pedaling along before I've got much chance of coming up with anything decent. And then I just have to hope that I get N before the bike slams into a brick wall....