I'm so there. I think I hit that stage maybe 4-6 weeks ago, where things I thought mattered or would stress me out just didn't anymore. I officially give zero fucks about them. The latest iteration - people adding guests to their RSVP. You were invited as 1, RSVPed for 2, if it means that much to you to add someone then I just don't have the energy to care about it. Sure friend, bring your SIL. Whatever.
On a related note: the budget. We're under budget just barely right now, but probably won't end up that way. Whatever. We have the money. So no Mom, I don't care that you look at me as if a bear just ripped my arm off when I casually mention something about an entree being $34. Be glad you don't know the full cost of any of these things because you'll surely stroke out comparing it to your own wedding in 1981. So when you ask me "just how much are you spending on this thing?!" I'll just shrug and say "just enough."
What did you originally think was a Really Big Deal that you now give zero fucks about?