[vtry]

Yup, same experience here. If someone well respected leaves, moral can be completely destroyed. That person doesn't even have to be an important person.

One of the most interesting type of personality is the useless guy who brighten the office up, once they leave, the whole office can fall apart, especially if the office is full of strong personalities.

[tutufan]

Yup. Yourdon (or somebody like that) noted the example of an apparently useless team member that had the notable property that whenever he/she joined a team, the project became a success. I've subsequently looked for such examples, and have spotted several likely instances. And perhaps more importantly, I've realized that I can try to be one myself (hopefully without also becoming "useless").