Conversation about Mother's Day

I have this friend whose mom died of cancer when the friend was a child. Said friend is having a going-away party this weekend, on Sunday. I called another friend to see if she was going to the party since, you know, girls can't, like, go to parties and stuff if there aren't going to be other friends at the parties.

Me: Hey are you going to the party on Sunday?

Her: Yeah, I am... Wait. Sunday?! My mom will be here. It's Mother's Day! Who the fuck has a party on MOTHER'S DAY!?!

Me: Um, someone whose mom died when she was 8?

Her: Whoa. I forgot about that. I'm such an asshole.

Me: Yeah, don't feel bad. And you are talking to me right now, not her. A couple years ago I decided to call all my friends and other random people to wish them a happy Mother's Day, and I called her and was like "Hi! Happy Mother's Day! How are -- oh shit, sorry! I forgot! Are you O.K.?!" Talk about awkward, I felt like such a retarded friend.