Notice my use of the term "understand". If you are just using from some library quaternions as a black-box, you really needn't understand anything about them, b

Notice my use of the term "understand". If you are just using from some library quaternions as a black-box, you really needn't understand anything about them, but if you want understand them it's probably easier to go through geometric algebra first. Otherwise you're basically just learning geometric algebra with half the rules missing and it makes no sense.