郭德纲家训引争议

Famous crosstalk actor Guo Degang wrote a letter to his son on the boy's 18th birthday. In the letter, Guo warns his son how evil and dark the world is. The letter says: "Asking for help is more difficult than touching the sky; Human hearts are more dangerous than jungle; friendship is more fragile than melting ice. Once you enter the wild world, forget about integrity and morality. Don't believe people who praise you; Don't listen to people who swear at you." Since Guo posted the letter on his official microblog, many web users criticized that Guo shouldn't reveal too much dark side of adult world to young children. Do you think Guo is doing the right thing? Do we need to tell kids the darker side of society?