history: A couple years ago I forgot my grandmother's birthday. I felt so bad about it. I forgot about my grandmother's birthday a couple years back. I felt so bad about it! Oh no! It happens to the best of us :) Have you talked to her about it when you remembered?
current: Absolutely! I called her the next day and made sure to visit her. :)
next: Awww I'm sure she completely understood and really appreciated you reaching out and going to visit her!