It may not come as a surprise that Philip Larkin has provided us with a mordant explanation of What Life Is Like. But an admirer of Larkin (me, for instance) might add: "Yes, mordant and witty and laceratingly honest and -- perhaps -- an explanation which may be absolutely true (at least for 'one man once')."
Continuing to Live
Continuing to live -- that is, repeat
A habit formed to get necessaries --
Is nearly always losing, or going without.
This loss of interest, hair, and enterprise --
Ah, if the game were poker, yes,
You might discard them, draw a full house!
But it's chess.
And once you have walked the length of your mind, what
You command is clear as a lading-list.
Anything else must not, for you, be thought
And what's the profit? Only that, in time,
We half-identify the blind impress
All our behavings bear, may trace it home.
But to confess,
On that green evening when our death begins,
Just what it was, is hardly satisfying,
Since it applied only to one man once,
And that one dying.
Philip Larkin, Collected Poems (Faber and Faber/The Marvell Press 1988).