Doing surprisingly well

Its been just 3 weeks since my father passed away and I am surprised at how I am feeling pretty much back to normal. I feel a little bit guilty about that because it seems too soon. I know that others suffer with grief for much much longer. Maybe it will return with a vengance, I don't know. But for right now, while I miss my dad and I still think abut him often, the thoughts usually do not make me much sadness, not like they used to. I think it was that I already was grieving his lost for a long time before he actually died. He was is such bad shape he could not do much of anything, and barely could talk, so in a way it was like he was already gone. So I had grief of the lose plus the pain of having to see him suffer. Now there is no more suffering. I know that is over. Plus I understand that he was very old (90) and so I cannot feel too bad, for most people do not get to live that long. I am thinking that he lived his life and lived it well, and now I need to do the same. I know that is what he would want.