In summary, what are your thoughts on what it takes to be successful?

[Belacqua]

Is "success" judged internally or externally, or, both?

To me the internal sense of a person is crucial to judging success.

If the external measurements are money, fame, being top in one's profession, etc., but one can have these things and still be miserable, then I don't think they can equate with success. 

I'm not taking about a happy mood -- like always being in a Coca Cola commercial. It's more like satisfaction, not being wracked by desire or obsession. The ability to "be here now," at home with what you are.