im trying to have spooky thoughts

Actually, many people believe that Confucius was the first teacher in the world, but no one can know for sure. So, while it is hard to know exactly who was the first teacher ever or who taught the first teacher, what is certain is that their legacy continues to inspire educators and learners throughout the world today.

well...
the first teacher was actually taught by the first teacher which means the first teacher wasn't actually the first teacher meaning the first teacher was the first teacher to teach the first teacher so theoretically speaking there was no first teacher to teach the teachers

God taught the first teacher cuz he's all knowing

The teacher taught HIMSELF not herself.

oh boy

Good question :/