Every human, since they were born must have been taught about good things and how they live with a good way of life in the world. They should keep it until they grow up and eventually die.
Therefore, they have to try to appreciate every person in this world. Yet before that, they ought to self-respecting as complete as they want to be respected. And in line with the process, they're required to be able to interact with others. Some elements of that interaction needs you to show how much you respect to others, how much you appreciate to others and also how your attitude works toward people around you.
And once more time I say that it's not about how old are you, not about child, teenager or adult. We have a dose at the age of each of us about it. So, don't ever say that you aren't old enough to appreciate a person.
Because, basically what you've done to others is something that will be happen to you in return. Everything that happens to you is a form of reflection about what you have done.
Don't think that everything you have done will be just happen to you back. It can happen to people who you love the most in your life.
My mom always warn me about it, and I always try to implemet it in my life everyday. It's one of the things that I cerish in this life.
That's why I always try to do it. I have one determination ... " Always try the best for all people regardless of who they are before ....."
With love :)