We must allow our kids to fail and learn from it

We must allow our kids to fail, the earlier the better. The earlier they realize about "人外有人，天外有天”， the better.  When my daughter was at elementary school, she failed at one of the competitions miserably,consider that she had always been winning in the past years.  On the way home, she cried and cried and tried to justify what had just happened. Though I did not tell her or show her my feeling. I was very glad that it happened. It made her realize that there are people smarter than she is, more talented than she is, and more skilled than she is. She may vaguely remember the event now, I consider it as an important lesson.