[Photo by Clem Onojeghuo at Unsplash]
I have been present when the most appropriate reaction to a person's resignation or retirement would be the rending of garments and the gnashing of teeth.
Because a huge amount of institutional memory and wisdom is about to walk out the door and in most organizations there is little likelihood that it has been preserved. If you maintain a policy manual you're ahead of the game but far too many organizations don't. Someone leaves and the place suffers for years. Even if things are written down, the subtle lessons are rarely preserved.
Having the person leave an audio recording of what he or she learned could be invaluable. It doesn't need to be comprehensive but preserving some insight on the small but important points could pay off enormously. It will be far more valuable than a gold watch.