Life Is Bookended by What We Cannot Experience
A life has boundaries that are unlike its other events. We remember childhood imperfectly. We remember yesterday. We can anticipate tomorrow. But the time before our birth is not part of our first-person memory. And whatever follows death is not available for ordinary first-person report from within this life.
That creates a philosophical asymmetry. The middle of life is crowded with experience. The bookends are known indirectly.
Through biology. Through other people's observations. Through religious and philosophical traditions. Through inference and belief. Different traditions make different claims about what, if anything, precedes birth or follows death. Those claims should not be presented as settled facts merely because the boundary is mysterious.
The mystery itself is enough. A life is lived between limits that the person living it cannot inspect in the same way as ordinary experience. That can sharpen humility about what we know. It can also sharpen attention to the part between the bookends that is actually available now.