Kindness vs Cruelty

Many students in different schools now a days have lesser and lesser feelings. They laugh at the mentally challenged and physicaly disabled of other people. What is wrong with the mentally challenged and physically disabled people? Aren't they still humans? Why do people criticise them so much? What if one day, you become physically disabled? What if one day you lose your sight? Won't people laugh at you like you laughed before? What if you are born mentally challenged? How would you feel if you are laughed at? Won't you feel equally upset and ashamed like the mentally challenged do.
It is already very bad to be born with a defact. Wouldn't it be worse if one pokes fun at them? Why do people just need to do this? Is it for the sake of having fun? Or is it purely done in spite? How does it feel for you to be look down on, to be trodden on like dirt? People who are disabled did not have a choice to be born with a disability. It is not as simple as saying, "Oh, I want to be born healthy and normal."
The disabled have no choice but to resign to their fate! People should never make fun of them. I believe that everyone is kind. However bad you might appear, under that wicked exterior, there is a kind heart.