Get over yourself...

When is right to say to someone that they really should get over themselves? I mean is it possible that people over appreciate their own self worth? I believe so, sometimes someone does a great job at something one time, and that can be many years ago, but they keep measuring their importance by the actions or success of the past. Hmm? I can't understand it, maybe it's just a being humble thing? If one is humble, which can be difficult for everyone from time to time, but if one tries to be humble and straightforward and not forgetting honest about the facts of any issue... well, then maybe one will have a better chance of living in the now and in the near future, instead of hanging on to the past successes or failures... is it possible? Hope so da.