That is a strange thing about Dutch indeed. We do really like to use constructions with the question word 'waar', even if we are not talking about a certain place. You may have noticed that the Dutch word for 'why?' is 'waarom?', literally translated rather 'for where?' than 'for what?'. The same hapens to the answer on the question waar? (where?): daar (there). Some examples: - Waarom vraag je dat? (Why are you asking that?) - Daarom leer ik Nederlands. (That's why I am learning Dutch.) - Daarna ga ik naar de winkel. (After that I('ll) go to the shop.) - Daar wil ik niet over praten. (I don't want to talk about that.) - Waar gaat het over? (What's it about?)

One thing that might help you is that you can't use "wat" with a preposition. The sentence "waar wacht je op" has the preposition "op" (op iets wachten), so you can't use "wat" here. With a sentence like "wat verwacht je" (= what are you expecting) there is no preposition, so you should use "wat".

thank you! so confused about when to use "wat" and when to use "waar"

Lukas gave you a great answer. I just want to add that in English you can also say "wherefore", which is the same as "for what reason".