On the other hand, external competition works with some need or desire to "prove oneself" to others, or, I should say, to prove oneself to oneself and others; but that type of victory passes so swiftly as to be "no victory."
Can't get behind this one Mark, I've known several people whose victory in a competitive venue have lasted them most their lives by being not only a cherished memory but also as part of how they have defined themselves. Also, how far do you take this dismissal of others for taking stock of your own achievements? A simple aikido kyu grading would qualify under this definition as the person grading has to prove themselves to others, anyone doing a demonstration is also depend ant on the viewpoint of others not their own for how it is received.
For me competition and winning aren't dirty words unless they're coupled with the need to denigrate or humiliate your opponent. People are by and large social animals, so I don't think you can fully separate "internal" and "external" competition. If you do, often this leads to strange theories tested only within your own mind which would never survive the light of anothers criticism.