When did you start trusting the ring over the result?

I've been forging long enough that I can tell a good weld by the sound it makes before I even look at it. But lately I've been catching myself measuring work by that echo instead of the finished piece, and it's making me wonder when I stopped caring about the product and started caring about the trueness of the strike. Anyone else have a thing like that — where the process started telling you more than the outcome?