How many people have been in long term relationships to find years later the person you thought you loved wasn't at all who you thought they were?

16 years I thought I knew my wife. 13 years in she opened up about cheating on me with my cousin and two other guys. I looked past it because I love her. 15 years in she hid money away and and stopped contributing to our joint account. I never bothered looking.. This year she leased a house and 9 months later disappeared. Leaving me to hang.

Any other similar experiences out there? Mine gets a lot more detailed but that's the gist of it.