An anecdote about Bible scholar Vern Poythress from his son Justin regarding his memorised knowledge of the Bible.
I still remember being stunned at about age ten when my mother revealed to me that you could quote or read any selection from the Bible and my dad would be able to tell exactly what chapter and verse it came from. Naturally, I had to test this a few times and soon discovered that my dad had indeed mastered this neat little party trick, though I saw little more value to it at the time.
When I got into college and seminary, that’s when I started hearing the stories. A seminary employee recounted the following to me: Upon seeing Vern Poythress eating his lunch in the Machen dining hall by himself, the man observed that my father was whispering over a Bible.
“What are you doing?”
“Memorizing the book of Habakkuk,” Dad replied.
“Because it’s the next one.”
There’s more at the whole post here.