I would have to say my grandfather (my mother's father) who passed about 7 years ago.
I would want to spend some time with him to go fishing with him (his favorite thing) and to listen to his stories of when he was growing up (so wish I had recorded all of those stories....as they are now long gone). AND I would tell him that I am sorry for not being there at home when he passed...we all knew it would be soon, as he wished to be home, instead of the hospital...but we went out of town (and I knew it was going to be that weekend, I had that feeling)....but we went and we were not able to be there at his side. The family said that the preacher was talking to him and saying prayers....Papa had one tear fall and a big smile on his face when he passed. Love you Papa!!!
