Having too much Brain is bad for you. It demands your attention, constantly knocking your reality door, pestering for this and that. Like a purpose. Or meaning, as if the sheer joy of being alive isn't meaning enough.
Over thinking, fighting back against any attempts at meditation or physical discomfort, it demands to be noticed. The constant nagging to be entertained, flitting from one experience to another in some strange desire for success (and, therefore, immortality).
It's only when you calm it down that you start to see real change. The path is revealed in the silent moments between synaptic impulses.
Too Much Brain will eventually go away, but you will continue long into the deep night.