In the last issue of the New Yorker, there's a fascinating article about how
the brain gets to the "aha!" moment (as opposed to the analytical answer).
Not surprisingly--right brain. Also not surprisingly--the best way to get
to the aha moment is to allow for meandering. Read it if you've a chance.
"The left brain is good, but the right side gives the entire mind its reason
for even thinking in the first place."