There are a few trophies/achievements such as "Thinker" and "The Big Thinker," which seem to be awarded for thinking a certain number of your own thoughts.
I've noticed very rarely that I have thoughts appear underneath me that are a jumbled mess of other things' thoughts that I've seen or heard up to that point, but these are few and far between and show up without any sort of pattern. Is there anything I can do to make myself have my own thoughts more regularly, or do I just think things completely randomly?