Perhaps this isn't the right Forum for such topic, but it does fall under some philosophy. Your brain thinks not all at once but in a progressive nature where you cannot possibly consider all thoughts at once of a subject or any multiple subjects. I believe it is a combination progression, and this how thought builds. To put it into an example, Say you were in the middle of a discussion and something comes to your head to say. What put it there? I believe this is a combination of multiple concepts/thoughts that 'connect the dots' over the subject. It's like your brain is constantly searching for a thought. Now, this would lead to progression of a thought just like Newton or Einstein.. Putting 1 and 1 together = 2. 2 then = 1 and it repeats itself from the new perspective/thought. It's a building progression of combinations. It is simply random until put into context. That is why you cannot think everything at once.