I would think the coming of photography a rather big thing. Modern times would be the same without it ;) but the leader of some group, somewhere, for a few years. People know.
I might be slightly biased, cause I am interested in inventions. But even if I didnt know it, I think my opinion would be the same. That it is weird how we dont know about the origin of some things that play a big role in our lives, but know some other trivial things in great detail.