Gratitude.

Everyone has standards. A set of rules and principles. To live life by, to avoid certain people, and to befriend others. Formed by experience, people,moments. 
Stick by them. Don't bend or break them for anyone. Except maybe your parents. But that's it. Nobody else deserves it. Not another single person in this world can, and will make the effort to prove that they can be better than the principle you made. And if someone is, seriously respect them and keep them. And if nobody is, you'll end up regretting having bent your own will to match someone else's.
Some people can't take dishonesty. Others lying. Maybe smoking. Or drinking. To each its own. And you don't need to justify it. You're human. The world is viewed with a million eyes in a thousand different ways. Perception is relative. We're all scattered. The least we can have is our own opinion.
And nobody should talk you out of it. Tell you it's no big deal. That just because they don't hold the same principle/point/standard, it means it isn't important. Or worth considering. In fact, make that another principle. Avoid anyone who talks you out of your beliefs.
Stand for something. Always. Stand for things that will make you a better person tomorrow.
You're you. No one does it better.