The writer is someone who plays with the body of his mother.
The past is always tense, the future perfect.
译文:假如让青春年华虚度,到年老时只能悔恨不已。赏析:人生短暂,年华易逝,我们要珍惜每天的日子,不要蹉跎岁月。
The only thing we can know is that we know nothing and that is the highest flight of human wisdom.