I'm a big advocate of thinking and especially abstract lines of thought. Pondering the imponderable. That being said I'm of the opinion it needs a counterbalance and for me that's meditation. The concentration and clarity of mind it cultivates is a force multiplier, sorting out the wheat from the chaff so to speak, allowing greater engagement of the wheat and dismissal of the chaff. Call it enhanced discernment. It also allows for total disengagement from habits of mind and to just rest in pure being, absolute stillness.

As far as what we are? Nothing effable though we can rest in the Ineffable. I know I have a face whether or not I'm looking in a mirror. Were I deaf, dumb, blind and paralyzed from birth I'd still know I exist. That "knowing" is our intrinsic nature.