Not sure if these are the worse, but they can be a bit stressful: School dreams. I get those every now and then and it seems to have several reoccuring themes, sometimes all in the same dream.
- forgetting where a certain class is
- forgetting my locker combination
- forgetting where my locker is, sometimes forgetting my combination too! So I need to brute force each locker.
Funny thing is I've been out of school for over 10 years.
A newish theme, being in class, and having a sudden realization that I havn't been to math class in months, and realizing that I have not been looking at my schedule but rather just remembering it from memory... except for math. I eventually wake up, then I go into panic, thinking "wait, when IS the last time I went to that class?" Takes me a bit then it's like "ohhhh right, I'm not even in school anymore, thank God!".
I'd say the ones that are even worse though are dreams about waking up, usually dream that I wake up, and take my shower, and do all that stuff. Only to wake up and realize that I dreamed all that, and then having to do it all over again. It's like "I just did all that! Now I have to redo it".