I saw a "story from Greek mythology" referenced in my morning paper, and I'd never heard it before.
A woman came to the River Styx and asked to be taken across into that dark land. [The ferryman] Charon reminded her that the dead were offered the option of drinking from the River Lethe, whose waters removed all memory of previous existence.
She wanted to know, “Will I forget how I have suffered?” Charon replied, “Yes, but you will forget how you have rejoiced.” Then she asked, “Will I forget my failures?” Patiently, Charon responded, “Yes, and your victories as well.” Finally, she wanted to know, “Will I forget how I have been hated?” “Yes,” said Charon, “but also you will forget how you have been loved.” After a few moments of reflection, the woman decided to leave the waters of Lethe untasted.
This story is entirely new to me, and the only references I can find are other people saying "There's this Greek myth..."
Is this in fact an actual myth? What's the origin, or at least what's the oldest version recorded?