Disclaiming Banner: I still exist. I still don't have the copyright for ATLA.

First

Flying for the first time made finding that Aang kid worth it in Sokka's mind. Even if this bison thing was a giant, fluffy, snot monster, it was now upgraded to a flying, giant, fluffy, snot monster. Very cool, very repeatable.

It genuinely counted as the first good surprise in his entire life. Katara did not count. She sneezed icicles when she was a day old.

But for that first moment of discovery, the world fell away. He wasn't a too soon adult. He was just riding on a weird, living, breathing, wonderful creature and only they and the sky existed.