Are self-improvement and being yourself mutually exclusive? Which is more important?

Whenever questions like “How do I impress this person?” or “How do I become popular?” are asked, there is a prevalent response: “Don’t worry so much, just be yourself.” For the most part, I agree with this sentiment; it’s very important not to sacrifice your integrity to achieve a goal. However, I have a problem with the implication.

I think we all have small qualities or characteristics that are recognized universally as “negative”. I’m not talking about personality quirks that create individuality, but specific negative attributes.

Instead of “being ourselves” should we pursue to improve ourselves in the long-term by eradicating these “bad” qualities? If so, how do we make sure we don’t lose track of what makes us who we are? If not, should we just embrace these imperfections? Which qualities should we seek to keep, and which to ditch?

What says The Collective?