Why GR has not entered high school education yet
Being introduced to general relativity, learners face a twofold challenge: First, they have to discard their traditional worldview that has been cemented by years of school education. At the same time, they have to handle new and abstract concepts of space and time that often contradict their everyday experience.
---by "contradict" means talking nonsense. After teaching "traditional worldview" the education system next step is to introduce nonsense to its students, and accept that it "contradicts" what it had earlier been teaching!