I read in sci.electronics.design that Robert Baer wrote (in ) about 'website for bids on a design wanted!', on Mon, 28 Mar 2005:
It is for some people. For some of THEM, a lot depends on experience. But I've noticed that when Fred Bloggs is in a 'mural' phase, a response, with mural (a very large ASCII schematic), appears extremely quickly after the original enquiry. I suspect that at least some of these solutions DO spring, 'fully-formed' into his mind. To what extent Win has the same experience, I wouldn't venture to speculate.
The Welsh have a word for it, it's the state of mind of a bard when he is inspired by his 'awen' (Muse). I have experienced it (in electronics) successfully twice. In both cases, a problem was described to me and the non-trivial solution instantly appeared in my mind - no reasoning or calculation at all.
Of course, you do get false inspirations as well, but there is a difference; you 'know' that the real ones are true, without a shadow of doubt. It's like 'lightning calculation', I feel sure, and I sometimes get it when searching for an anagram - a true anagram 'feels' correct.