Inventing stuff in the past
Years ago I read a good short story about a young artist that got caught in some kind of time warp and was transported back to the 15th century. Since there was no way back he made the best of it.
He tried to use what he knew to invent things like the airplane and the helicopter. He had to be careful not to design something so exotic he would be burned at the stake or something.
Unfortunately, he had no engineering skills and lacked the ability to recreate anything revolutionary but he became famous as the artist Leonardo Da Vinci.