When I was younger (19 or so) I had an.. um... let's just call it a mind-expanding experience. It became so clear to me all of a sudden just how far we as a society are from our roots, or from our foundations. I mean this in a pretty concrete way. From a handful of extended family tribes living close to the earth, we built up these incredibly complex civilizations - technology, religion, bureaucracy, global transportation, trade, electronics, communications. We take it all for granted: cities, highrises, airplanes, universities, supermarkets. But most of it is pretty new.
Catastrophe is always lurking around the corner, as a potentiality. Climate change is one likely trigger for many potential catastrophes, and it is possible that our civilization will end with it. Think about Rome. It was around for a thousand years, and it fell. In post-Roman Britain, for instance, with nobody to maintain the infrastructure in the cities there was hunger and plague. People pretty much abandoned the cities and went back to barely scratching out a living, with small scale subsistence farming. These were what we know as the Dark Ages. If it could happen then, it can happen now. And eventually it will. That is certain; the time frame and causes are less so.
Humans have found and continue to find many solutions to the problems of survival. We must fulfill our needs for shelter, food, companionship, etc. But we have a lot of flexibility in exactly how we do this. The incredible variety and creativity of solutions that people have found become apparent when studying in a field like history (and probably anthropology, too). I love learning how different peoples have organized their societies: the religions and culture and social structures, the ethics and cuisine and mythologies.
In addition, if there are so many different ways we have organized our societies, than that tells me that this particular one is not the immutable reality. That means there is also hope for change. We can do things differently, because we have already done them differently in the past. I wrote a whole theoretical paper going into this in more detail - if anyone is interested, I can post it here (here, actually).
As some of you know, I'm currently working on an MA in History (and International Relations) and considering applying to do a PhD. Problem is, I am interested in everything and have such trouble deciding what to focus on. But I'm pretty sure at least that I want to stay in the field of history.