Of course Martin Luther could not be accused of hiding his real self.
“I sit here at ease, hardened and unfeeling—alas! praying little, grieving little for the Church of God, burning rather in the fierce fires of my untamed flesh. It comes to this: I should be afire in the spirit; in reality I am afire in the flesh, with lust, laziness, idleness, sleepiness. It is perhaps because you have all ceased praying for me that God has turned away from me…. For the last eight days I have written nothing, nor prayed nor studied, partly from self-indulgence, partly from another vexatious handicap [constipation and piles]…. I really cannot stand it any longer…. Pray for me, I beg you, for in my seclusion here I am submerged in sins” (E.G. Rupp and Benjamin Drewery, eds, Martin Luther: Documents of Modern History, pp. 72-73).