The plane of air is one that holds no planets, one may find a rock floating about or a lake that moves freely about, but while here you will find yourself floating, buffeted about by the air for the most part.
Everyone knows the things like "you can't lick your elbow" and things like that, but did you know you can't hum while holding your nose? Go on, try it! It is also really hard to swallow while holding your nose. Not impossible, just hard. Try it!