Do you remember A Conneticut Yankee in King Arthur's Court?
A 19th century smith is transported back in time, and wows King Arthur with modern technology.
If that happened to me, with 2 centuries more technology, they would be considerably less impressed.
What would I do? Build them an airplane? How about a computer? Umm. A car? Anything?
I think the best I could do would be to pull out my cell phone and show them the screen lighting up (until the battery ran out)!
I'm not worried that I am going to be swept back in time (with a career as the Village Idiot), but it is an uncomfortable realization that my own level of technology- the things I understand well enough to recreate, is probably lower than that of the average person 100 years ago.
My friend Bill, on the other hand, probably doesn't need to worry about these things!