Scientists have found that trees grown in an artificial environment with little stress in their lives grow fast, but are extremely weak and prone to falling. Upon further investigation, they found that trees only put out long roots and reinforce themselves under normal stresses such as wind, rain, and the various growing seasons.
So could stress be good for us?
I think so.
Think for a moment about the people you respect in this world. Are they worthy of your respect because they grew up with a silver spoon in their mouth or because they overcame adversity? My guess is you respect them because they overcame a lot of difficulty in their lives!
Stop worrying so much about what happened in the past or what might happen in the future. Live, and realize that the rough spots make us stronger. The saying that whatever doesn't kill us makes us stronger is apt, although maybe it should be whatever doesn't break us makes us stronger.
Learn to stretch right to that magic growth spot where you have to work and might fail; there is no growth in the comfort zone. Just don't go too far too fast. While some wind is good for the tree, too much at once can break it, and some wounds are slow to heal.