When I was growing up,I had an old neighbor named Dr Gibbs.He didn't look like any other doctor I'd ever known.He was a very kind person..After he retired,he began to plant trees in his large garden. He wished to make it a forest. The good doctor had some interesting ideas about planting trees.He never watered his new trees.Once I asked why,he said,"If you water them,each baby tree will grow weaker and weaker. Otherwise,they will have to grow deep roots to look for water under the earth by themselves." He planted some oaks, and instead of watering them every morning,he beat them with a rolled-up newspaper.I asked him why he did that,and he said it was to get the trees' attention. Dr Gibbs died two years after I left home.I always walked by his house and looked at the trees that I'd watched him plant about twenty -five years ago.They're very big and strong now. I also planted two trees several years ago.I carried water to them for a whole summer.I sprayed them.However,after two years of caring too much,whenever a cold wind blows in, they shake a lot. Life is hard,whether we want it to be or not. What we need to do is try our best to make our roots reach deep into the brave heart,so when the rain falls and the wind blows,we could face them strongly and won't be beaten down. What's the main idea of this passage?
We should try our best to make ourselves strong enough to beat difficulties. We should beat trees with rolled-up newspapers. We can't grow up without our parents' care. We shouldn't  water the new trees.