It would be fair to say that, of all the things in the world, I am most interested in the human lives that were lived before about 500 years ago. I'm not completely uninterested in the modern world, or in the Columbian Exchange, or in the industrial revolution, or the impact of the various European empires on the world since 1492. It's just that I'm significantly more interested in the world before European domination. I'm not uninterested in natural history, either: I'm just a bit more interested in understanding sentient life.
The books I buy - and I'm drowning in a sea of books at home - are either directly concerned with ancient life in some part of the globe or indirectly informative about it.
I have several books about ancient Indian Ocean trade and none on the modern trade on the same seas. I have several ethnographic works about people living in New Guinea but none of them deal with the impact of Christianity, because (while that's certainly a fascinating and important topic in modern New Guinea) it's not really helpful in understanding what life may have been like in New Guinea before Europeans and the sweet potato came along. The only books I have on Britain and Europe are on the medieval period and before - anything else would just be a distraction. I'm interested, too, in the entire world before 1492: wherever humans lived, and not just wherever we can look at documentary evidence.
There are a number of reasons for this. One is that it is much harder to find out about the world before 1492 than it is to find out about human history since then; it's more of a challenge. It requires skills, like language reconstruction and archaeological interpretation, and sometimes comparative ethnography, that I think are inherently interesting and enjoyable to work with. That's a key motivation, and it's one of the reasons why I'm so attracted to Indonesia: it takes time, effort, and skill to learn about it, and that makes the trickle of paydirt so much more rewarding.
Another (more important and edifying) reason is that I think the lives of the people who lived before 1492 - the vast bulk of humanity - have been unfairly neglected, and the people who lived them have been treated as fundamentally non-human exotic objects. People these days think of medieval people as so different from modern humans that they'll soak up all kinds of idiotic myths - like the one that says that medieval Britons drank ale because the water was too dirty. Partly this is due to sheer distance in time, but it's also to do with relevance: modern folk don't think ancient folk are relevant to their lives. That might be true. But I think it's myopic only to care about the things that directly affect your life. 'Useless' doesn't mean 'worthless'.
Millions of people lived in the 'Aztec' Triple Alliance, and they lived full and varied lives like those of others humans. Recently, their marital practices were made a prop in a US Supreme Court opinion (wrongly, I think). Crack open a history of the world at the middle: if the narrative hasn't already gone through the whole of the fifteenth century I'll be quite surprised. I don't think this kind of thing is right.
I believe sentient life is valuable. That's not based on religious reasoning or anything like that: I just value my own experiences and I'm curious to know what it would be like to live someone else's life - to know what foods they tasted, what emotions they were expected to feel, what social pressures, cosmologies, and art forms they were troubled by. I want to know wie es eigentlich gewesen ist, because knowing what it was actually like for people living in other times and at other places strips away the exoticism and puts us in their place. That means I'm interested in a certain kind of ancient history, and it's usually not pure political or military history.
It is hard to take on board right away - it takes effort, I think - but the people who lived in pre-Columbian Tierra del Fuego had the same ability to experience the world as you do. (I'm sure you'll agree with the statement right away, but it will still take a while to fully consider the implications of this.) They lived human lives - like yours and mine, but with completely different experiences. It would be a sad world if nobody tried to grasp what those experiences were through the limited evidence available to us.
And it is worth remembering that all of the things we have today came ultimately from the everyday acts of people in widely dispersed places on the planet: it would be wrong to simply ignore that in the focus on later developments. More importantly - I think more importantly - knowing the ancient origins of everyday things enhances our experience of the everyday things.
Trying to understand the lives of people who lived so long ago is primarily an intellectual task, but it's also an exercise in compassion. And I don't think this compassion needs to be directed towards achieving a particular goal in the present day to be worth something.