How I learned to say NO

At the peak of my success in the US as a keynote speaker, I was depressed.
I realised that more success actually meant more sacrifice, and the more success I wanted, the more I had to be willing to give up, and at that point in my life, it was my relationship with my wife and my newborn son.
I had to learn what level of success I wanted and how much I was willing to sacrifice. And that's when at the peak of my career, I had to learn to say no. I packed my bags and went back home to Australia and began to recalibrate my life to focus on what was truly important.
Where in your life have you had to learn how to say no?