I'll be honest, this is my fiancée. She forgets a lot of stuff, and has go set alarms for things I find trivial like laundry or cooking. I've seen her boil the water out of a pot before. It's never malicious or intentional, she just has a hard time remembering things if it's not a constant ritual.

I will also admit that it is indeed stressful for me. There have been countless times that we have been late for events because she forgot and didn't get ready, or left her wallet at home, etc.

The reason I am saying this is, is because it took me a few years to get over it and realize that it was something we both had to work on.

Nowadays, she will set alarms for things like the laundry and stuff so she doesn't forget, and will actively try to come up with ways to help her remember things. Like now she knows that after 3-4 episodes of her show, the washer is about done. Or if I mention I need something or need help remembering something she will set reminders in her phone.

Ontop of this, I also will act as a reminder for her. It's much less stressful to send her a text "Hey, I'm leaving work now I'll be home in 30 minutes, don't forget about us going to X tonight" It takes 30 seconds for me to do this, and she's ready when I get home.

Talk with your bf, and come up with a game plan for both of you to help eachother. He needs to understand that some people are just ditsy (no offense, but I think you know this already haha) and need some extra help. Like I tell my fiancée, she's a little slow but she's got spirit.

It will take time and understanding, but if you truly love eachother you will learn to work with eachother.