You can't go through life with a catcher's mitt on both hands. You need to be able to throw something back.
解释:砍伐树木不把树根砍掉,必能重新生长;堵塞水不把源头堵住,必会重新流出;消除祸患不铲除产生祸患的根基,祸患还会再生。
"The past is always with us, for it feeds the present."