IV. Death by Water
Phlebas the Phoenician, a fortnight dead,
Forgot the cry of gulls, and the deep sea swell
And the profit and loss.
A current under sea
Picked his bones in whispers. As he rose and fell
He passed the stages of his age and youth
Entering the whirlpool.
Gentile or Jew
O you who turn the wheel and look to windward,
Consider Phlebas, who was once handsome and tall as you.
I get Phlebas mixed up with those lines from Shakespeare's "The Tempest", where we get the idiom "sea change":
Full fathom five thy father lies,
Of his bones are coral made,
Those are pearls that were his eyes,
Nothing of him that doth fade,
But doth suffer a sea-change,
into something rich and strange,
Sea-nymphs hourly ring his knell,
Ding-dong.
Hark! now I hear them, ding-dong, bell.
Memento mori is just the ultimate reduction of the sentiment.
The whole stoic philosophy behind it is interesting. It's not just that you will die no matter how long you can put it off for. Once you are gone all that's left of you will be memories and descendants.
Even if you are remembered for a long time, like for example someone as famous as Marcus Aurelius, those memories aren't you they're just a reduction. You're gone forever.
You could extend that to consider the self you were 10 years ago. That you is also gone forever.
All in all it can be a freeing thing to contemplate. All you have is the right now so enjoy it or at the very least bare it.
https://imgur.com/B7snnCR
Rough translation:
As you are, so I once was As I am, so you will be