The people nobody notices notice everything, including who noticed them.

Being overlooked gives you a clear view. When nobody is performing for you, you see how people behave once they think it does not count, and you keep an accurate record of who was decent anyway. That record does not disappear when circumstances change. It just becomes relevant later.

Make a habit of greeting whoever the room skips: the new person, the quiet one, whoever is working while everybody else socialises. Do it because it is right rather than as a strategy. Being noticed is remembered for a very long time.