What are the skills and knowledge you could actually bring & fully realize at some point in the past?
And we're taking this in the strictest, nerdiest, materialist lense. I don't care how smart you are you ain't making a steam engine the in bronze age, for instance.
So what could you create, with just your knowledge & period tools? What kind of institutional, technological, philosophical innovations could you realistically recreate? How would you interface with the social fabric of society to not be some crazed pariah who never positively influences the place they went?
That was the Greeks, and it was regarded as a curiosity and certainly wouldn't actually be effective as an engine.
The Romans had something similar, too, but it was also just regarded as a curiosity since the rich asshole class couldn't see a way to turn an immediate profit off of it:
https://www.youtube.com/watch?v=5uqPlOAH85o