I Cant Believe How Ungrateful Some People Are

Planned a birthday party for two months for my mom and today is the day. We spend all day trying to keep it a surprise. This person takes her here, that person takes her there. I run around getting last minute things. Get to the place and she wouldn't come in. I ask her why and she's angry that no one told her. She feels she's been lied to. She tells me to my face that she wasn't going to this party. I ask her if she would be that selfish and she says yes that she'd be that selfish. So I said whatever and tried to leave. It wasn't until she saw all the people here that she changed her tone. I feel so stupid. I spent a lot of money and time. I was hoping she would at least like it and appreciate the gesture.