Role Reversal?

From The Last Season, by Eric Blehm:

Randy escorted his father back over Shepherd Pass - an easy stroll for him, but Dana showed his years, however slightly, by inquiring, "Is that the top?" about another false summit. Or "How many more switchbacks to the summit?" "Thirty years after my boyhood, the roles are reversed," wrote Randy in his journal. "Aren't we almost there, Daddy? How much farther?" (In some cases it takes a lot less than 30 years. ;=)