The mind that becomes soiled in youth can never again be washed clean. I know this by my own experience, & to this day I cherish an unappeased bitterness against the unfaithful guardians of my young life, who not only permitted but compelled me to read an unexpurgated Bible through before I was 15 years old. None can do that and ever draw a clean sweet breath again on this side of the grave.

The Writings of Mark Twain (ed. 1923)