This is an accurate description.
This is also why I try, whenever possible, to compose at least the first couple sentences of the next bit of writing while I’m standing in the shower with my perfect realization fresh in my mind. I have been known to hastily dry off and dress while repeating to myself, over and over, “Susan sat dejected over the remains of her breakfast. “More poutine?” asked the goat.” And then I hope nobody distracts me before I manage to get to the computer.
Of course, I’ve got about a fifty-fifty chance of having mis-remembered the last bit of writing and those fresh new sentences not being at all suitable for following it, and then I get to do the whole “wut r werds” dance.