letting go of the past

I just finished reading a new earth, a book well worth reading. I actually recommend it to more or less everyone. am re-reading it again, and will probably write some more once I finish it, but for now, here's a nice story from it:

Tanzan and Ekido were once traveling together down a muddy road. A heavy rain was falling. As they came around a bend, they met a lovely girl in a silk kimono and sash, unable to cross at an intersection.
"Come on, girl," said Tanzan at once. Lifting her in his arms, he carried her over the mud.
Ekido did not speak until that night when they reached a lodging temple. Then he could no longer restrain himself. "We monks don't go near females," he told Tanzan, "especially not young and lovely ones. It is dangerous. Why did you do that?"
"I left the girl there," said Tanzan. "Are you still carrying her?"

Now imagine what life would be like for someone who lived like Ekido all the time, unable or unwilling to let go internally of situations, accumulating more and more "stuff" inside, and you get a sense of what life is like for the majority of people on the planet. What a heavy burden of past they carry around with them in their minds.

(I copied the story from wikipedia, and the final paragraph from the book.)