Hole built for the water to swamp flowers

I remember when I was 4 and my grandpa had a big white dog. He was old, already, but ofcourse I didn't knew. I remember (How a kid is), always sleeping on him or even hitting him but he never minded. My grandpa said: ,,Don't hurt him for your own sake", first I was confused and said: ,,But it doesn't hurt him", and my grandpa said: ,,Because he knows you're a kid. And you explore hun", I didn't realized until he died. I was angry because my grandpa didn't cry that day but he said: ,,Nothing changes when you cry". As I got older, I heard how he died. He fell in the water hole my grandpa built for the flowers. I don't wanna know what kind of grief he felt that day.