The creation of the Universe.

[InsaneApache]

No, every thought comes from a combination of outer impressions, memories, and the way my brain looked when I was born. No thought comes out of nothing.

That's not true.

Einsteins' theories weren't from memories or outer impressions nor was he born with them. The brain is a very complex thing and only now are we beginning to understand it.

Also, where does the thought go once you've had it?

[Rodion Romanovich]

Einsteins' theories weren't from memories or outer impressions nor was he born with them.

Of course they were! To simplify things a lot, the system is very much equivalent to a module where you process data, and one module where you store it, and one module for receiving impressions (data) through senses. His theories stemmed from his fantasy, his prior knowledge in the subject, and his abilities to compare the memories he had to each other, drawing new conclusions. Then he had to store these new insights as memories, from which he could deduce new theories. His prior knowledge came from processing and storing the impressions from the outside. His processing ability came from earlier experiences (from the outside) and earlier thoughts.

Essentially the brain is actually built up much like a computer, the only difference is that it's a computer that is a million/billion/trillion times more complex than a normal computer, and that it can rewire its own hardware when needed, and that most of the constant wiring is part of a billions of years long evolutionary process. Can you really give example of a single thought that isn't built on memories, impressions and processing of those impressions and memories?

Also, where does the thought go once you've had it?

Either to the memory, or it reaches a dead end and is discarded, or it is transformed into output in the form of say a movement, something you say, or something else.