I walk on the beach and I see my tracks being left behind on the sand. The tide, however, arrives and washes them away, deletes them from existence. That is how lasting I am. However, I happen upon a rock half-buried on the ground, resisting once and again the crashing waters. Remaining.
I keep walking. Then, when no one is watching, I stop and scribble on the wet sand. “Memento Mori”. That, at least, can be taken away as well.