Where we come from, it's very different. Our elders are revered for their wisdom and experience, and many of them, despite their age, are still great masters, Benders, and warriors. While there's nothing wrong with being young, for a warrior, they want to be seen as older and more experienced.

A lot of the people on the ship are from different cultures. Before calling them nicknames, you might want to find out what their cultures are like first, to make sure what you're calling them isn't somehow offensive.

It'd probably be fun! You could learn about different cultures and make new friends in the process.