Was reading Plato's Protagoras lately. Definitely one of my favorite dialogues. There's a whole discussion in there that fascinates me where Socrates tentatively identifies The Good with what brings pleasure (leaving aside his intentions for this move). It's almost as if it makes it formally simpler to discuss the nature of courage and excellence in general when something has been specified as the referent for the The Good. This allows a formal analysis of what courage might be like, even if the referent for the The Good will be subsequently changed. (And the reader is expected to make this substitution, since identifying the The Good with The Pleasant is able to provide any reasonable explanation of the phenomenon of being overcome by pleasure. This phenomenon requires are more complex understanding of The Good, whatever it might be.

One of the things that seems to be going on here is that different kinds of "goods" can be resolved:

1) Protagoras is primarily interested in seeming good before the public for egoistic and financial reasons (and his evasiveness during his discussions with Socrates, and his inability to really compete with Socrates in dialogue is partly due to this)

2) Socrates is primarily interested in something we might call "actually being good".

Both these forms of excellence, or striving after excellence are a different kind of excellence then the natural excellence displayed by Alcibiades or Charmides -- a natural or potential excellence. (Like "daring" is the kind of potential courage or natural courage that must become real courage via learning.)

Protagoras overwhelming desire to appear good before others prevents him from being able to try to become genuinely good. And it also prevents him from even appearing good to others when he's compared to someone who's actually trying to become really good (like Socrates). And by the all the dialogically evasive maneuvers Protagoras makes during the dialogue, it would appear that he's trapped by this desire of his.