Robert E. Lee, around age 38, and his son William Henry Fitzhugh Lee, around age 8, c.1845
Excerpted from "Life and Letters of Robert Edward Lee: Soldier and Man" by John William Jones and published in 1906:
The General [Lee] related a pleasing incident of one of his boys with whom he was walking out in the snow one day at Arlington. The little fellow lagged behind, and looking over his shoulder the father saw him imitating his every movement, with head and shoulders erect and stepping exactly in his own foot-prints.
"When I saw this," said the General, "I said to myself, it behooves me to walk very straight, when this fellow is already following in my tracks."
This sounds like great advice to me. And based on all the accounts I have read, it appears General Lee took his own advice to heart.