Why would a senior employee keep tricks of the trade secret from others? For one reason only: a lack of confidence.
Someone who acknowledges his own talent and thinking skills would not be intimidated by others having the same abilities. Someone committed to team success would ensure knowledge is public — that is, known and available to many — and not private — that is, known only by himself.
In this podcast I provide examples of how and why to ensure the knowledge of your organization is not lost when someone walks out the door for the last time.