Quotations and Literature Forum

Hello.
I hope someone can help.
The quote is something like this:

"When I was 10 years old, I thought my Father was stupid.
By the time I was 20, I was amazed at how much my Father had learned in 10 years."

I have always believed it was a quote from Mark Twain, but a friend recently told me he always thought it was from Will Rogers.

Thank you (out there in Quotation Land) for your assistance.
Bob

When I was a boy of fourteen, my father was so ignorant I could hardly stand to have the old man around. But when I got to be twenty-one, I was astonished at how much he had learned in seven years.
~Mark Twain, "Old Times on the Mississippi" Atlantic Monthly, 1874

The quote is attributed to Twain and has his "flavor," but it is apochryphal. It has never been found in his writings by Twain scholars. Also, his father actually died when he was 11.