You think your accomplishment was a game-changer? I guarantee you The One-Upper did something better. And he’ll gladly tell you all about it in great detail.
You increased sales by 50%? Too bad The One Upper had a 60% spike last quarter? And while it’s very cute that you were Employee of the Month, The One-Upper was Salesman of the Year – for two years in a row. Whether these milestones were actually reached or (more likely) The One-Upper is bending the truth a bit, either way it’s obnoxious and can very easily squash morale in a team setting.