What had happened in his life to make him change so?
What had happened in his life to make him turn from everything he knew?
It could very well be the last good thing to happen in my life.
How often had this happened to him in his life?
He knew that something important had just happened in his life.
Never had such a nice thing happen to him in his life before, I should think.
You learn a lot from things that happen in your life.
That's the way the big things happen in your life.
It's one of the most important things to happen to me in my life.
It had never happened to him in his life before.