Why do so many of us have the same stress dream?

Its the perceived bottleneck for future success.

Because most humans were forced to go to school, and due to being human and similar circumstances, experienced school often as stressful and traumatic.

It’s a perfect setting for stress experiences. Dreams are often packed with symbolism, analogy, and metaphor. A stress dream is about your emotional state, right now, today, but school is a likely setting for it because there are so many ways for school experiences to mirror whatever present stresses you’re having.