I remember one moment in particular. I was fifteen years old and had been heavily into photography for about two years. I'd taken many very decent photos and had them displayed on a wall. My mom invited one of her acquaintances over for coffee and to talk to me about working in her family's photo studio some day. The nice lady pointed to a portrait of my grandfather and commented that she really liked it. She asked, "Other than technical accuracy, do you know what makes this a very fine portrait?".
I could not answer her question. I was completely stymied and somewhat stunned. I thought I was pretty darned good at photography because I knew more (technically) than the professionals I'd spoken to. The thing I'd fallen completely in love with (photography) had suddenly smacked me down and let me know I didn't know as much as I thought I knew. I could see and feel... and I could take the images... I was good at the technical aspects... but I didn't know what made them good. That one question made me think and wonder for a very long time.
That one simple question led me to learn more about the emotional aspects of photography and it still affects everything I do. Until that moment, I never thought it was important to analyze the emotional aspect of anything that's so technical in practice. I think this question affected my photography as much as any other thing before or since. I wish I could thank that fine lady right now but she's long gone.
I wonder how many of us wish we could thank someone for their positive influences in our lives but failed to recognize it at the time and we waited until it was too late.