Aang pretending to be Katara and Sokka’s grandfather and son respectively [episodes 1x05 and 3x02]
You find, after a journey, that you are not the person you used to be.
"Of Aang’s three children, Bumi was the one who most encapsulated his father’s penguin-sledding spirit."
- Bumi’s Bio on The Official Nickelodeon Website.
"Air above me, earth below me, fire within me."
I’m 98.9% positive that Aang’s last words to Katara were,
"Thanks for penguin sledding with me."