Change Ourselves to Become Better...?

Everyone in the world has their own personalities....
So am I!
i follow the wind...but i like to play around with water....
Why?
I sometime too angry,
but sometime I'm happy...
Why?
i know,
every people are bornt different...
But the question is
can we change ourselves to be better?
Are we supposed to change ourselves?

Even though God creates us different from others?