Why?

Why am I not my parent's child?
Why am I not my siblings sister?
I am a person full grown and relatively mature.
I have habits good and bad.
Yet I am not a ..
I do not think, live act like a ...
I have a brain that thinks.
I have a mind that imagines
Oh how it can imagine when it likes.
But for all I am there is one thing I am not. A ...
They are different, narrow minded individuals who love to gloat.
Who live for tragedies, bad days and bad things.
Who like to pick the bones from an argument, not once but several times and then before they spit them out they do it all again.
I'm not a .. am I?
No, I can't be a ..
I take joy from simple things of nature. A squirrel running across the path in front of me.
A flower i see blooming for the first time.
The sound of bird song waking me in the early dawn.
They don't hear or see this.
Why?
What gene was in me and lost by them?
What gene in them that didn't start in me?
I'm not sorry.
I'm glad.
But still, it makes me think.