Musings on St. Paul's Letters

I wonder (and suspect) if Paul ever wrote his letters over prolonged periods of time.

    If I am to live in the flesh, that means fruitful labor for me. Yet which I shall choose I cannot tell. I am hard pressed between the two. My desire is to depart and be with Christ, for that is far better. But to remain in the flesh is more necessary on your account. Convinced of this, I know that I will remain..."

So he apparently went from indecision to decision in just a few seconds?  Or there are the more lengthy letters like Romans. I can imagine him dictating one thought at a time to his secretary then perhaps coming back to the letter later.  The letter may be quick (relatively) to read but think about something you yourself write, be it a letter, document, paper, magnum opus, etc.  You don't just sit down at one sitting and pump it out (or maybe you do!).  It's written over days and reworked and rewritten.  Of course, we don't exactly how the inspiration of the Spirit played out either.

I can imagine Paul and Tychicus reaching the end of Romans 11

    Oh, the depth of the riches and wisdom and knowledge of God! How unsearchable are his judgments and how inscrutable his ways!
    “For who has known the mind of the Lord,
        or who has been his counselor?”
    “Or who has given a gift to him
        that he might be repaid?”
    For from him and through him and to him are all things. To him be glory forever. Amen.

And Paul saying, "Alright, Tychicus, what else should we do but walk around the lake and sing?"  Or imagine the original letters themselves.  Tychicus probably had handwriting I don't have, thus it was legible, but more than that I suspect, he wrote with a style appropriate to the words. I mean, what kind of depth and elegance must he have used with the above words?!