I think of this quote all the time; it is so true! Don't you find yourself talking like your colleagues? Starting to react in the same way your best friend does to a situation?
Sit down and make a list. Who are the people you spend the most time with? Be honest. People from work? Family? Neighbor? Girl from yoga class? Are these the people who you would choose to shape your values and help you become the best version of yourself? I hope so! You may become an average of the 5 of them.
The second part of the quote is important. "Choose carefully." We do have a choice!