The one leaning on the wall at the party usually understands the room better than anyone dancing in it.

Taking part costs attention. When you are in the middle of something, you are managing your own piece of it, which leaves almost nothing spare for watching. Standing slightly outside is not a failure to join in, it is a different position with a genuinely better view, and the person by the wall often knows exactly who is avoiding whom. Neither spot is the right one; they just gather different information.

If you are usually the observer, use it on purpose this week and notice one thing about a group you had missed. Then walk in anyway, once. Both readings are worth having.