The platonic dialogues should be read as a puzzle book. At the end of reading, you must formulate your own answers to the questions asked. Everything else is just a shallow entertainment 😛

At some point, I realized the nature of virtue. 

It might not be exactly what the ancient Greeks were talking about with virtue, which we translate as virtue. Who cares? Let them have their concept of virtue which is basically manliness, and let me provide an answer as to our concept of virtue. 

Virtue is when you are disposed to do good things and not disposed to do bad things. 

If you know a little philosophy, but only enough to get you in trouble, as many of my friends do, when I say the above to you you might be tempted to say "so what are good things and bad things?" I laugh at this pointless cliche. When giving a conceptual analysis, or indeed a definition, we don't have to run the gamut of the entire dictionary, to the ground. You might as well as me "what is 'disposed' and what is 'to'?" That would help about as much.

This clear concept also allows us to solve several other puzzles of the platonic dialogues. 

Is virtue one thing or many things? It's one thing, but can have component parts.

Is virtue teachable? To the extent that you think dispositions can be taught. So, ultimately, yes.

I haven't bothered to address any objections or counter-arguments that someone could bring up here, not even those contained in the platonic dialogues themselves.