I've had those on and off in 25+ years since HS/college, but they've been more ... regular in the last few years. Not every night, but I think I have "didn't go to class" dreams (nightmares?) probably every other month now. Usually it's a college class, not HS, but same thing. Sometimes when waking up... it still feels real, and I need a moment to double check I'm really... here and not in the past about to fail a test.