I never had a grandparent until we moved back to Italy when I was 6.5yo.
When we moved there we lived about half an hour's walk from my grandparents house and I spent so much time there I can remember, even now, the smallest details like the smell of particular cupboards; the sounds different doors made; the routines, and jobs we all had to do (grandchildren) like mopping the floor after lunch.
I can remember the lining paper she had on shelves; the first sounds of the cockerels; the exact way you had to turn the tap on outside to get it working.
The smell of pomodori being processed for the harvest. Lying out in the corn that had been left to dry out and getting a smack (for my grandfather benefit) but a big kiss and some icecream when he wan't looking 
I could walk back there tomorrow and it would all be different as she has passed on, and I wish, from the bottom of my heart, I hadn't been so unbelievably stupid as to not go back (for lots of reason, none of which are bloody valid).
I'm sure lots of my childhood would have changed anyway, even if I had gone back, but maybe they would have been gradual changes. You know., The tap night have been fixed. The paper in the bottom of the cupboards would have been different...
But I know that I can lie down in bed tonight, and I feel so lucky that I can walk my way through that house, the out buildings and the farm and recall all of it. Sight, smell, touch. It's all still there. And I am so grateful as it was the most beautiful, happiest time in my life.
And it was all down to my utterly beautiful, ridiculously strong (in many ways) Nonna.