Wow, I got my first "That comment was too long". Okay, I'm breaking this into two replies because it's just too good to not put here.

I ended up getting a better job overseas (paid to research and code what I want). And then I quit that and ended up getting an even better opportunity after travelling again, and after a fun period interning at a magazine, then making investment banker money for building an ecommerce site.

I think the more glibly you express it, ("Quit your job! Travel the world!" would have to be one of the more concise expressions) the more possible meanings that statement can encode, so the more open it is to interpretation.

I think the essence of being successful doing that (by essence I mean one main cause and requirement) is simply the willingness to leave one opportunity to find a better one.

From a thermodynamic viewpoint, the more you raise your energy (unbound state), the more possible energy states you can access. The more "stable" things are, the less energy states (read possibilities) you will access.

From an "multivariate optimization" perspective (how you maximize your utility over a couple of metrics relevant to you with the space of possibilities some kind of undulating surface) you are searching the landscape of possibilities, the willingness to "pivot" off a local maxima and begin searching again is a strategy that makes finding higher peaks possible.

Diving deeper, heuristically the landscape is large (there are many possible configurations of your axes of utility, i.e, many possible situations), and also mostly self-similar (because there are certain rules which operate in the world which cycle and combine to produce familiar patterns, for example, human psychology, means that, broadly, people's reactions to a given situation will mostly be the same across cultures, and their motivations will be similar as well, such as in aggregate people are motivated by their fears (of not having enough, of shame) and by their ego (competing with other egos), and by their culture (social norms, shared history and cultural identity), and by what the narrative they choose for themselves (hero, victim, "normal", "outcast", "individual" roughly corresponding to high school film tropes, thou becoming more multifaceted and specialised with age -- people become niche experts at being who they are, is another way of saying habits become ingrained). So these personal identities and cultural identities drive people, and these identities are shaped by forces uniform across the world, and people drive the world, so the world, in most ways you look, is essentially the same. It is also very very different, yet the difference is obvious. The sameness merits mention because it is one of those "hacks" that is not always inherently obvious, and even when it is, there's a lot of depth to the self-similar characters of different places, and a lot of utility to be gained by learning about what's similar wherever you are.

So back to the "optimization" analogy, if we are walking a landscape that has two characteristics, it's large and mostly uniform, there are some consequences suggested by these observations. If I'm on a local peak in a large landscape (i.e, I have one a many possible jobs in many possible places), and that landscape is mostly uniform, then there's probably a lot of other peaks even a far way away.