It's perfectly normal. You cared about them while they lived, and it's not as though you wanted them to die. You're just able to accept that people die and, for want of a better term, there's no use crying over spilt milk. I was the same as you when my grandfather died. He used to live with us. He basically raised me, and I definitely loved him the most out of everyone I've met to this day. When he died I didn't react in the conventional way. I just continued as normal. However, if you don't find yourself carrying on and occasionally bursting into uncontrollable tears, suddenly you're an asshole, or a psychopath, or autistic, or angsty, or you're still in shock and the tears will come later. It's all nonsense. It's possible to have loved someone in life and also be able to accept their death without a massive fuss.