We know from the Frozen II soundtrack that Josh Gad’s big song in Frozen II is called “When I Am Older” so clearly growing up is really on Olaf’s mind.
Since Olaf was a brand new creation in the first Frozen, he had the mentality of a child.
This last scene likely gives us a strong indication of just how Olaf’s character has changed, and will continue to change, since the first movie.
Doing it when you’re the world’s only magical living snowman is probably a bit more complicated.