Here's Francis Crick, one of the discoverers of the structure of DNA, on how it feels to make a scientific discovery:
is not easy to convey, unless one has experienced it, the dramatic
feeling of sudden enlightenment that floods the mind when the right idea
finally clicks into place. One immediately sees how many previously
puzzling facts are neatly explained by the new hypothesis. One could
kick oneself for not having the idea earlier, it now seems so obvious.
Yet before, everything was in a fog."-- from What Mad Pursuit
I thought this might sound familiar to writers, because it's also a good description of making a creative breakthrough!