Drawing the line

I was listening to a program on NPR recently, and I heard the interviewee say something interesting about discovering the guitar. Paraphrased, it was:

If you were to draw a thick black line through my life, one side would be "before-guitar," and the other would be "after-guitar."

It's interesting to reflect on the thick black line test. I honestly don't know if there's a single moment in my own life when everything changed, but I've clearly got a few dark gray lines at various points. What about you?