The best advice I have ever got from one of my mentors:
“Your caliber is not measured by how indispensable you are to your team/company. What really matters is how successful you have been to ensure that things go on smoothly even after you are gone”
– Ravi Ranjan, Tavant Technologies.
And that is when I decided to get involved extensively in documenting EVERYTHING that I do for the team. It helps me (in the events of memory failures,which are quite frequent) and also the team when required.
It also highlights the importance of grooming team members to take over your tasks in case you decide to go on long leave / resign.
Alas, these two basic facts are often overlooked, thus landing the team in trouble – usually adding to the woes during crisis.