Undergraduate / Teacher in management, an unforgettable person whom you have encountered in your life [7]

I took cbest writing twice but couldn't pass that.I believem i am struggling with my writing skills.I posted this topic on this thread, can anyone make my essay correct as per the standard english rule. Thanks.

Essay Question:Write about an unforgettable person whom you have encountered in your life. What made him or her special? How did their life impact yours in a positive or negative way?

Here's the essay respose:
Life is full of unexpected experiences. Sometimes, it happens that when one met with a person who changed his/her life completely. In my life, I also encountered with a person who changed my way of thinking and she was my teacher in ...