I spend plenty of time thinking about the kinds of questions most ambitious college students do: how should I prepare for the future? What kind of career should I pursue? What’s worth learning?
Most of my college friends plan their next semester, next year, and the year after graduation. Most of my friends in industry plan about as far as their next job. This is a pretty good strategy. I don’t believe in planning any further out than a couple of years, because I can never predict how things change in my life. The future is hard to predict.
I don’t mean you shouldn’t think about the future and have long-term goals. You should have an idea of where you want to be four years from now. Maybe even ten years from now. But you shouldn’t start from where you want to be four years from now and plan out the steps in between . The details of the future are hard to predict.
But if it’s possible to have some idea of where you want to be four years from now, it’s also possible to have an inkling about the world fifty years from now. We know that the world fifty years from now is going to be completely different. There we have it - we know something. Compare the 1960s to today: a total transformation. In the 1960s the Vietnam War was escalating. Cancer was a death sentence. Colonialism in Africa was still unwinding. ALGOL was just invented. The civil rights movement in America was beginning. 
Society will change. Even if you don’t share my beliefs about the direction of the future, and even though you can never predict how things change in your life, you can predict something: change is coming. Technological change, social change, and economic change. It’s obvious, but we don’t think about this much. We usually watch events as they happen, as spectators. Every so often we’ll stop and realize what happened. So it’s a useful exercise to think about the future now.
Some specific trends that I believe will play out in my lifetime:
We will discover magic (again). Life and society will be transformed several times over by advances in science and engineering. I don’t have a single shred of doubt about this. I can’t tell you exactly what will change, though, except that they will involve rapidly growing fields like biotech, energy, and computing . If only to prepare myself, I like to describe the future as having the kind of change we would call magic: sufficiently advanced technology.
We will live drastically longer lives. As a result of advances in medicine, I will probably live beyond the age of 120.
And there is some chance I will live to an age beyond 300.
Historical data actually doesn’t support this idea - in recent decades life expectancy has only inched up a year or so per decade (roughly one year from 2002-2010 in the US). This is a problem whenever you look at the past and try to use that to look towards a future of what I believe to be accelerating change. I still believe medicine will be one of the fields that is transformed in the next fifty years. The seeds have already been planted in genomics and biotech.
The divide between labor and capital will grow. During my longer lifespan, those with capital - financial resources, machinery, and organizational clout - will gain a growing and disproportionate share of wealth and power over those with labor - employment and time that people have to put into their work. This is closely related to rising income inequality in America . This will significantly alter the political landscape of the future.
We might be tempted to believe this is an trend that we or society will stop through political action. I read an interesting idea on this: with increasing inequality, larger and larger swaths of the populace would be excluded from access to wealth and power. Most modern nations are democracies, so rising inequality might eventually be checked by majority support for redistributive economics policies (heavier taxes on the wealthy, and so on). But I wouldn’t count on this to let us safely ignore the trend. Inequality will continue increasing for some time. Entrepreneurs and those with capital, expertise, and financial resources will generally emigrate to nations with less economically restrictive policies (more economically liberal policies). And technology is inherently a multiplier on productivity - even if the rising tide of technology lifts all boats, it will still widen the gap.
I don’t believe in planning too far for the future, but I always try to keep these trends in mind.
These ideas as a whole don’t paint a clear picture of the best path forwards. The concentration of wealth in those with capital suggests entrepreneurial careers or careers in leadership. The scientific revolutions that await us suggest deep study in rapidly advancing areas like biotechnology, computing, or energy. And the long lifespans we will enjoy suggests taking time off - after all, we have long working lives ahead of us.
You can’t ever optimize over everything, so picking the two trends you think are the most likely and will have the most influence on the future paints a clearer guiding path. If you believe science and the labor-capital divide are more relevant, that would direct you towards an entrepreneurial career in science. If you believe science and longer lifespans are more relevant, that would suggest a career in research - the academic path takes a long time, but you’ll live longer. And if you think longer lifespans and the labor-capital divide are more relevant, that suggests pursuing any relevant entrepreneurial or leadership career that you enjoy.
What do you think? Let me know!
A crazier side note:
I am much, much less convinced of these things, but I foresee two outcomes for us over the next two centuries or so. Humanity reaches an unimaginably advanced level of technological achievement (exponential technological progress), or we end up killing ourselves off. This binary outcome is a fun thing to think about, but not anything that applies to decisions I make today.
 A microcosmic example of this is planning out college. Originally I carefully planned out all the classes I’d take during my four years at Berkeley. That plan was abandoned within my first year at Berkeley because I realized: 1) the professor teaching a class is the most important factor (and it changes every semester), 2) every semester I’d learn about a new topic I hadn’t been interested in before, and 3) new classes emerged every year.
 With hindsight we can notice the seeds of the fifty years that followed. Chemotherapy had barely emerged, and is today firmly established in medicine. African nations - independent - still struggle with the legacy of colonialism. And computing has exploded and taken over our lives.
 I have no idea if I’ll live to see specific technologies like artificial general intelligence or whatever else is going to be hyped tomorrow.
 Income inequality in the United States. Income inequality is falling globally - but largely due to the catch-up development of the third world, where people are finding employment as inexpensive labor. Labor holds value in the third world, ironically contributing to the decline in labor’s share of wealth in America.