Well, no kidding! What are you saying?
The point is not that complicated. There are times in life when we cannot shield ourselves from pain and failure. We will get hurt. We will get sick. It's an unfortunate part of life.
The solution is in our reaction to such pain. If we get knocked down and stay down, we will never make the kind of progress of which we are capable. On the other hand, if we never allow ourselves to fail, we will probably not ever have a complete picture of reality.
I want my students to learn from pain and failure. I want them to learn from their mistakes and the mistakes of others. Let's not pretend that we are bulletproof; some of those bullets hold great teaching potential.