As a goalie, it is impossible to succeed more than you have failed. Unless you shut out every single game you have ever played and your team has managed to also win all of them there is no perfect. Even in a game that your team comes out the victor you likely made mistakes in the course of that game that cost your team points.
This is a great thing about this position. You have to know how to lose, how to live with your mistakes, how to isolate a mistake so one action doesn't turn into a snowball effect.
In life this is very important. Many people allow one bad thing in a day to ruin their entire day(I can't say that I don't do this as well at times) but what you need to do is be able to move forward and put that one moment behind you. Learn from it if you can, but move forward regardless.