I fervently believe that childhood development is in its highest gear from the ages of two years old until puberty. This time period has been conclusively stated to be when full mastery of any language can occur, and basic personal traits begin to emerge and refine. If a childhood would behave in a limitless manner within this time period, I'm afraid they'll naturally become accustomed to unruly and frivelous behavior.
I believe that children should have limits because they don't know what is best for them. Also they should have to understand that they have to strive for what they want. Also things don't come to those who don't work for it. I feel children need to understand that while they are young so when they get older they will know to strive for nothing but the best.