You've been lied to before.
People will tell you anything when they're looking you in the face, especially if their aim is to a validate a confrontation or any form of discomfort.
What really matters about you is what people are saying when you're not around. That's when you get the realness.
With no possibility of tension and without having someone to please (you), a person will say exactly how they feel about you.
And the things that get said about you when you're not around is the impression the world will have of you. After all, there are only so many places you can be at once. Your reputation, however, travels faster and further than any human being ever will.