It's all about being specific and interesting.

Example:

My father is a successful business man. I grow more and more interest in finance seeing him making business with many other people. ----> Failed.

My father expanded his loan shark business at his 40 (interesting point). I have been so amazed to learn that there is much profit on the difference between the interest he earns through the loans disbursed to customers and the interest he pay to his deposit customers (your finance sparks). So i decided to join finance...bla bla bla ----> Much better.