If you don't show up for the wedding you can tell Sparky you forgot what day it was.
True story: I was married during my third year of medical school, while I was working 100-120 hours a week in the wards. (That's 12 hour shifts 6 days a week and overnight every third or fourth night - yes, it's stupid. Nowadays we have laws limiting it to 80 hours a week but I think even those are flaunted). Your brain can get pretty addled from that kind of sleep deprivation.
My ex was still in the classroom part of med school so his hours were much less.
Anyway, we were getting married in his home town on the opposite coast and he flew out a couple weeks before the wedding to finalize all the preparations. I was flying out a few days before the wedding.
The night before my departure, I was carefully packing my bags, including my paper ticket for my flight in the morning (yes, kids this was in the Dark Ages when you got an actual paper ticket). Then I notice the date on the ticket - I was supposed to have flown out THAT morning, not the next day! Thankfully the airline cooperated and let me fly on the same flight the next day.
I've often wondered since if that wasn't my subconscious trying to stop me from marrying him lol.