Just beat Highest Rated Player: Honest Opinion?

After 15. ... Na7 why not Nd6? Rather then doubling his rooks you may double his pawns and thereby acquire the bishop pair or simply threaten b7 or bring your rook to c7 and be supported by the knight.
17. ... f6? 18. Bd6! strong like bull.
20. ... Nc6 so confused had your opponent become that he dropped his knight. Had he not drop his knight however the position is still good for white as after the demise of the white squared black bishop black has doubled pawns on the f-file and two isolated pawns what more could you ask for.
You may consider yourself weak but look at your game your instincts seem quite good. Fat Lady is correct by the way the maneuver with the Queen to b5 was slick.

Simple game really - he just didnt see Qb5 and after that it was all over. You played me once and you should really have got a draw, I think you are a much better player than your current rating, especially if you dont know openings. Happy to play again anytime.