Too few parameters, too few dimensions, just amplitude/quality and duration. If there were more you'd have to be smart to find it interesting. Why is thinking so complex and multi-dimensional? You actually have to be smart to find it interesting. Does evolution select for people who find thinking difficult? It kind of seems so. Is there a benefit to that? Or is the difficulty inevitable, like lifting something heavy has to be difficult, require more effort by design (of the universe). Surely even a semi-smart AI from the lowest rungs of mind-design space would be bored to tears by our, er, "thought" processes...