I took my grandfather to the lake to leave him there and never come back
What do you mean? Did he come back?
Unfortunately he did.
Abandoning elderly relatives is horrible treatment of people you should be caring for. You ought to be in jail for what you tried to pull.
It was very relaxing in the great outdoors. I loved it! I thought he would remain there.
Ideally, you're expected to take care of your grandpa but if you're unable to do so, you should put him in a nursing home. It's pretty horrible to leave him stranded somewhere.