An Arrow and a Longing
One cannot step into the same river twice; that much is clear to me. The connotations of that phrase, however, are multifold. Heraclitus was referring to the constant state of flux that the world is subjected to. That, of course, also applies to our psyche. The reason we can never go back to the same place again is because our dispositions change. It is thus that I find myself repeating like a mantra: “I cannot go back, only forward. I am an Arrow and a Longing.”

Clear, consise and wonderful :-) It's a good thing btw, not being able to go back, even when we might wish to.
Heraclitus is one of my favorites and a great influence on my thinking and writing. You might be interested in some of my articles at http://tediousexistence.blogspot.com.
Zeteticus
A timely reminder. Thank you.
Indeed -
"I cannot go back, only forward. I am now an Arrow and a Longing."
Beautifully expressed.