Knowing genetics makes you understand why and how you are similar to your parents.

Knowing that physical and psychological state are linked, and that they affect each other.

We have ways of introspecting one's mind and body and understand the the "whys" of being an individual and also Human.

Except genetics is too low level to describe anything but the most basic features.

On that matter - my dad and my grandpa were alcoholics; and thus I have the same vice if I don’t pay attention to my motivations in life.

However knowing genetics didn’t help me understand that :)