Practicing what I preach. This is a game from an OTB tournament last year. I confused my opening lines and got a worse endgame. Then I equalized... then declined a draw offer... then ground down my opponent.
Check out 41...a6!! Zugzwang! How did I learn to find things like this in OTB games? Certainly not by studying openings, or by arguing with people who are trying to help me improve.
As a more specific example of what everyone is trying to get through to you, the position you posted after 14.b3 - you know, the one that's "drawn, of course" - looks nearly resignable for white to me. I can confidently say I'd win 9/10 games with black from there, at least against anyone <2500 FIDE. Study endgames, and eventually you'll be able to get to the same place. Or, keep focusing on openings, and you'll get nowhere.