The way I kind of view it is that I am a very slow thinker, but I've overdeveloped the skill of self-investigation. So I can "think fast" by asking myself very good questions that quickly cut to the core of where my answer would come from. There are often questions or problems (especially in the world of engineering) where the best thing for me to do is something else and let my subconscious do some work on it. It's not that I couldn't solve it using "fast brain", it's just that using "slow brain" (often diffuse thinking) is more energy efficient.