Say that you in your present form accidentally fell into a wormhole and traveled back to your same town in 1975, and say that you befriended some of the inhabitants of that time and told them where you came from and they believed you. (No, you're not meeting your past self if you were alive then and you don't get to see your family). What would you tell the people about our lives in the year 2015? What would you have to say about our technology, medicine, popular culture, social norms, etc? I'm sure some people will have some not so great things to say about our time, but would your assessment of it to people in the past be more positive or negative? Mine would be fairly positive. We humans do some really stupid crap, but realistically we always have. We just didn't have the technology to record every single second of our lives as they occur. I would try to describe smartphones to the people of the past. I would tell them that we humans have given ourselves abilities that they could never dream of. I would tell them of all our new vaccines and cures for things and new medical knowledge. I would tell them how bad smoking really is for them, especially indoors. The world must have been a smelly smokey place back then.