Have you ever been forgotten? Maybe your brother forgot your birthday. Or you spent hours on a project at office and your boss forgot about it, so your hard work went to waste.
No one likes to be forgotten, and for associations being forgotten by members can be disastrous. If members forget about you or your benefits, then there's no reason for them to participate or renew. That's just one of many reasons it's important for associations to stay at the top of their members' minds.