I decided to learn Mandarin partly for my grandma, and now that she's gone I just wish I knew more about her life, and her family before marriage, before kids, you know what I mean?
Now that I'm older and able to travel, I do wish that I had more time with her (as selfish as it sounds) and I miss her terribly. I ask my parents lots of questions though so it's not too bad!
Cherish them if they're good to you, most times elders can be awful too.