Without much nostalgia, I recall how recently my sense of self was a creature of what-comes-next. For years, everything seemed in flux: I was a student, always preparing for a career, knowing that the academics were not ends in and of themselves; I was an individual in that I could pick-and-choose my relationships and assume or abandon these almost at will; I was in transition physically and intellectually, not tied to any particular place, interest, or belief, although at any given moment I felt intensely dedicated to whichever places, interests, or beliefs I occupied and could not conceive of changing these.
Until we find our place in life, I think we exist in a bubble; conceptually, I see this bubble as most like an airliner on a one-way trip (bear with me on this). We make choices as to which airliner to board, and these choices are mostly but not entirely our own. Each of us chooses a destination, if only by process of elimination or by default, with some realization that that choice is important; it's always possible to return to your origin or to choose another destination, but to make those changes may be difficult generally, may be costly financially or in terms of lost time, may have collateral effects on others, and so on. At the very least, it may be embarassing to have to admit that you've chosen poorly or that you're poorly-suited to an otherwise fine destination. Even outstanding choices preclude other possibilities; you can't be everything all at once. To a lesser extent, your choice of destination or airliner is determined by external factors. An uneducated or unimaginative person may not know or care that some destinations exist. A materially-disadvantaged person may not have the option to travel in comfort on the airliner of his choice. Still, the uneducated can learn and the unimaginative can dream; any person can reach nearly any destination, although his trip may be longer, more difficult, or less comfortable than others'. Naive, perhaps, but who cares? I'm American.
Once on the airliner, we have some freedom of movement, but not much. Our choices are bound to a large extent by the strictures of our environment, the rules of others, and the whims of those in our immediate vicinity. Every so often, you find yourself stimulated by a chance meeting or conversation on an airliner, but on most trips you're not sitting next to me; thus, most trips are experiences to endure rather than to cherish. On the airliner you exist, but whether you become more than you were when you boarded is largely a function of what you bring on-board. Bring some work to do or a good book to read and you're better off generally than the passenger who sleeps through the trip or stares vacantly out the window for the duration.
More later . . . .