Just all the others I once went to my mate Emma's wedding - porked her in the past and her chief bridesmaid, but kept it a secret from my then new wife - always have secrets!
Get the date of the wedding engraved inside your wedding ring. Then you can always check it surreptitiously whenever you forget. If your memory is exceptionally fallible, you could get the wife's name engraved as well.
I'm always looking for the next ex wife. As Rod Stewart suggested, I just need to find someone who hates me and buy them a house.
I got married 01-01-01. Which is binary for 'youre fucked mate'. Still I cant forget it. Especially as we got together 01-01-91. Women love to remember dates. I can barely remember my own birthday. Which I was reminded by her was today.