Most of us would probably agree that kid-like qualities are cool. The ability to treat the world with wonder, innocence, respect, trust, and a smile are skills that are important to foster. Being able to frolic is right up there on my short list of critical qualities in companions. In many world religions, child-like behavior is encouraged for one reason or another. Studies show that laughter, skipping, and learning will keep you healthy longer.
Having said that, there is no excuse for not treating others as if you were an adult. Kids can be extremely cruel and selfish, albeit usually unintentionally. Their place in life is to figure out how things relate to them. To learn, to associate, to become. The responsibility of an adult is to behave, to create, to do, if you will. As such, we have rules about appropriateness, courtesy, and morality that are generally accepted to create our civilization. In most cases (the minor ones, nothing major here) we exclude children from these rules specifically because of their unique position in life. They cry out loud in public, they ask questions about how much other people weigh, they stare at the scar on your face without it being rude, they pretty much get to run around exploring and causing mischief because they are kids. And it's more or less okay...until it's not.
At some point, you have start treating others as if you were an adult. Conforming to rules of ettiquete and propriety. Being concerned about other people, instead of your own immediate need.
Because I travel all the time, I end up dealing with most of my friends from a distance much of the time. Finally I will plunk down with them for a couple days of hardcore fun and merriment and then I am off again to let them resume their routines. It is precisely situations like this which have crystallized for me the need to be playful and carefree at times, and the need to responsible, serious and courteous at other times.
My friends who can be kid-like slip easily into a weekend of laughter and companionship, experiencing the wonder of the world around us. Once sated we slip back to maturity as we face jobs, workout schedules, routines, households.
My friends who never slip the bonds of adulthood are never quite sure why I would pull the car over just to savor a sunset, or why my eyes grow wide at a juggler. They never get quite as excited as I do about the idea of Disneyland, watching animated movies, walking the waterfront, or the chance to see Cirque Du Soleil.
My firends who still treat people as if they were kids take so much more work to engage. I'd rather just not talk about them.
In the end, I find that the only practical rule I can follow is:
Treat People Like You Are An Adult,
But Act Like You Are Child.
But Act Like You Are Child.
It's more fun than you'd think. Less work than you'd imagine.