Totally lost a year

[LJSDesigns]

I was out to dinner with my family tonight to celebrate my DIL's birthday and we were talking that I was up next. I said I couldn't believe that I was going to be 54 this year and my sister started laughing and said that I was going to be 55. I was like no, I'm going to be 54. But after we did the math, then redid the math, it turns out I am going to be 55.

I feel like I lost a year of my life at dinner tonight. I don't even know when I started thinking I was a year younger, but it has been going on for a while now. I was convinced I knew my own age, but apparently I am losing my mind. The age doesn't bother me, much, but just knowing I forgot something so important about myself is a bit disconcerting.

Have you ever experienced something like this where you are sure about something in your life, only to find out that you're wrong?