Wait a minute, aren't quaternions super confusing? After all, they live in 4D space!!! Let's try to put this confusion to rest.
Watch 3Blue1Brown's excellent video on quaternions:
https://www.youtube.com/watch?v=d4EgbgTm0Bg&t=1s
Play with quaternions on 3Blue1Brown's and Ben Eater's interactive website:
http://3imaginary1real.com