Maybe there was something paternal about him. He perhaps has qualities that would be desired in a father, maybe knowledgeable, mature, etc. In jungian psychology dream interpretation, the characters in the dream represent aspects of the dreamer. Dreams are symbolic, not necessarily literal forms of expression. They can serve as guidance, warning, encouragement, and reflections of our subconscious feelings.
The history teacher could symbolize stability or patience. Maybe these are qualities you want to cultivate as a parent.
If you are a troll, you're certainly one of the more interesting ones@👿