I am letting go of all the past grudges.

A grudge takes upkeep. Somebody's name gets checked periodically. Their new job is noted. The story is retold at intervals to keep it in working order, and each retelling smooths it slightly, until the version being maintained bears less relation to the evening it came from.

That maintenance is the actual cost, and it is paid entirely by one party. The other person, in most cases, has no idea the account exists. Stopping the upkeep needs no announcement and no reconciliation. It is closer to cancelling a standing order to a place you stopped going years ago.