To Know What I Think

"How do you know what you think til you see what you say?" is another one of the many questions posed by our professor. His answer; write it down. Is this implying that one cannot truly know what they think until they write it down? or is it simply suggesting that the best way to put forward ones thoughts is in writing? this seems more plausible. I, for one, am constantly consumed by thought, usually unable to clear my mind even when I wish it to be so. Can it be said that I know not what I truly think until I have written it down? I think not, for when I write my thoughts out I am always left with the resonating feeling that something got lost in translation. The translation from thought to written word. I know what I think before it is written down but that remains confined to my own thoughts, so instead what I think this statement is suggesting is that our thoughts can't be known to others without first being put into a common medium, written language in this case, spoken word in others. Your thoughts are always know to you, so long as you're conscious, but can't be known to others without first leaving your head translated into a medium which the masses can access.