Junior dude in my team: Started working with the expectation to get dirty and go deep into technology (he was in fact a mathematician). The first two months he was happy like a little puppy playing around. Then suddenly he started talking about getting more responsibilities and beeing more a manager than a dev (because development is too stressful). Then on his last day of the probation period he quit out of nowhere because he got a job offer from a place he really wanted to go. He bought one beer per person in my team, but haven't invited my boss to that event. We suddenly realize why: He talked real shit about him!

What a dick!