Your friends really do make a difference.  "Whoever walks with the wise becomes wise, but the companion of fools will suffer harm." (Pro 13:20)

I used to work 911 and was assigned the weekend shift to deal with the wild nights at the bars. It was very easy to witness the harm that people shared among themselves, from lasting sexual diseases to death. Some things don't change, but you can change who your friends are, and what habits you have.