Childhood & adolescence is the time when we should encourage our children to find out for themselves what they are capable of. They need to be able to assess risk, make mistakes, learn by experience what the parameters of their capabilities are. They need to be able to deal with misfortune - things do go wrong occasionally.
If we are over protective of children they will become timid adults. They will be habituated to "fear based living". They won't have learned how to deal with adversity. They will have an unrealistic expectation that someone else will make choices for them & ensure that they are always OK.
Life itself is a risk, every moment of every day something bad could happen. But it mostly doesn't. Life is mostly fairly boring & predictable. Yes, dreadful things do happen, but you shouldn't live your life as though they are about to. If you do you are denying yourself & those you love real opportunities.
What we need to develop is a happy mind.
There are so many things to be anxious about in our complex lives today. You can be crippled by fear. Anxiety disorders are the plague of modern living. The charity Mind is a great source of help and information -
https://www.mind.org.uk/information-support/types-of-mental-health-problems/anxiety-and-panic-attacks/anxiety-disorders/#.XYjn_WZ7n7A
We have to teach children to trust their insticts & not be limited by fear. We have to send them out into the world as happy & confident people. We can only do that if we are not bound by fear ourselves.
Worry gets you nowhere.