It was a multitude of things. My oldest daughter was young enough that if I was able to quit she would never know I had ever smoked. A very close family friend had recently passed from complications from smoking. But the catalyst was a co-worker walking past me while I was smoking and said something to the effect of my life improving if I could quit. She was not preachy, nor was she judgmental about it. It was a simple statement. It made me think. Turns out she was a lung cancer survivor.