I had seen a funny yet honest video recently where they were talking about the reality of being stuck in the past. Unless you know how something was invented or how it functions, your knowledge would be pretty much useless.
If I transmigrate to the past (depends on how far back but let's say a century), I wonder if I would even be believed if I said anything about future developments. I would not even be able to make predictions for individuals to work as a shaman. I don't know if I would have the means to develop anything. Maybe if I found some rich or influential companionship then I could help develop ideas. The resistance to change would probably be immense. For example, people used to fear cars, the rich did not want to give up slaves, men did not want women voting, people refused to believe the Earth revolved around the sun, etc. Even today you'll even find groups that refuse to believe scientific evidence or are resistant to change.
I do find these dramas fun though but I don't know if I would ever want to travel too far back into the past unless I am a person of means. :)