Chances of gaining memory back after brain surgery?!

My grandpa is 80 years old. 9 days ago, he collapsed, was taken to the hospital, and had bleeding on the brain. The doctors think he had a brain anyeurism, and he had surgery to remove it. I went to see him yesterday, and he seems like he is doing pretty well, considering everything that happened. He can feed himself, he goes for walks, with the help of a walker, and physical therapist. He of course knows my grandma, and always wants to see her and talk to her. He remembers his three children, he knows that they have to put new cars on my grandmas car. He knew who my sister and I were...he remembered her name, he never said mine, but he asked about my husband, and also about how are jobs were going. One of his friends, whom he worked with for a number of years, came to visit, and my grandpa couldn't remember who he was. He got very upset, and it was really hard to see him break down like that. After a while, they got to talking though, and grandpa enjoyed his company with his "friend". :) Anyway, I just want to know what the chances are of him making a pretty full recovery. I don't want him to go to a nursing home...he wants to go home, and I want him to, too. Will his memory come back little by little? How long will it take? And what are the chances of him being able to return to life the way it was before this? Thank you in advance everyone.