Why do the best ideas always seem to happen in the shower?

Inc managazine article on perfect brainstorm and why do the best ideas always seem to happen in the shower?

Some findings -

Its better to write ideas down during a session
There should be plenty of breaks during the brainstorml
Best ideas come at the end of a brainstorm
alternate individual brainstorming with group sessions. Then there's what experts call "brainwriting." Rather than staging a face-to-face group, direct participants to write their ideas down on a piece of paper or electronically
Ask the right questions
Generate lots of ideas to find one good idea, generate-document-evaluate-execute

and finally answer to the shower paradox:
"Creativity requires an attitude that is a paradoxical blend of attention and relaxation". Shower gives you this as long as you are not in the plumbing business.