Yes, but I have done it my whole life! Missed college orientation because I got the weekend wrong.
Talk about feeling stupid!
I went to the DMV because my license was out of date and I didn't notice and I needed a new one. Waited for almost an hour only to find that I had been looking at the wrong date and the license was good for years. The guy was looking at me like I shouldn't even be driving!
Oh, and a real good one... teacher friend of mine was getting married. I was excited to go to the wedding. Bought a dress and shoes and everything. Morning of the wedding I got all dressed up, got in my car and drove the hour to the site worrying the whole time I was going to be late. No one was there.
It was Saturday, the wedding was Sunday.
Drove back home and and prayed the neighbors wouldn't see me. Next morning, did it all over again. I never told anyone! Smacking myself in the face is much less embarrassing!