My dad died on March 28, 2006. I'll probably remember that date forever. Although it's been nearly a year and a half, I still expect to see him watching the ballgame whenever I go into the basement. And I still have dreams where it's as if he never died. Strange because I've never had any belief in an afterlife. Maybe the dreams are just my mind's subconscious helping me to cope.
There are many factors here that might make you feel a deceased person should still be there. How close you were is certainly important. To be truthful, I was as close with my dad as he was capable of being with anyone, but he was a distant, difficult to get along with person who pretty much kept to his hobbies. I think in my case the biggest factor is that he was simply there nearly my entire life. I've never lived on my own save the first three semesters of college, so when he passed I had spent over 42 years under the same roof. It was just simply part and parcel of my life that when I woke up, he was there, even if I seldom interacted with him. I suppose in many ways my expectations of seeing him upon going down into the basement are much the same as seeing an old, cherished piece of furniture. You don't really notice it's missing until it's gone.
My father's passing in many ways was probably easier for my siblings. My sister has been married since 1993, on her own since 1989. My brother was on his own since 1995, although he lived six blocks away until three years ago, and often stopped by. Once a person is out of your life on a daily basis, it's somewhat easier to get used to them not being there. My father's mother died in 2002 but she had been living upstate for four or five years. Since I never had a chance to visit her after she left my uncle's house, it was as if she was for all intents and purposes dead already for a few years. I do miss her, but I wouldn't expect to see her if I visited my uncle's old house (he moved too). And she lived a decently long life (87 years, 4 months), which is another factor. I had expected to have my dad around at least another ten years. Although he wasn't in the best of health, neither was his mother at 71, yet she hung on quite a while longer. When he went I just felt as if a mistake was made, so maybe my expectations are based on my feelings that he shouldn't have died at the age he did. I was just reading today about Pavarotti. Same age as my dad when he went. I had the same thoughts on how he was taken before his time. Sadly, none of us can choose when we or our loved ones go. Some go too young, others are blessed with very long lives, but also at the same time cursed as they outlive everyone they ever cared about, sometimes even their children.