readoldthings

You're right, part of the magic of Forgiveness Vespers is that it's mandatory, and you don't get to pick and choose who you ask, and to whom you grant, forgiveness: "God forgives, and I forgive" But what if you've never met this person and have never had a chance to do them any wrong? It doesn't matter, because sin is illness, pollution, and we all have to live in the same spiritual environment-- which means every sin I commit even if it's only inside my own head (there's a materialist idea! That thoughts are located solely inside the skull! Ha!), pollutes the environment we all live in. We all have to live with the stench, and we are all of us, all the time, out there peeing in the pool that we all swim in. That is why we ask everyone, and that is why we forgive everyone.

So it isn't even always a case of "what specifically did I do to wrong this particular group/person"? It's broader than that. More like "What are all the ways I've made the world a worse place for everybody who lives here in the ant farm with me?" It's also why in the communion prayers we ask forgiveness for sins "known and unknown". We often have very sharp memories when it comes to other people's sins, and amnesia when it comes to our own!