if my memory serves me right

My grandfather was in the United States Military, an engineer.
Sometimes I think I am crazy. I feel waves of his presence near people who never even met him; I choke up when thinking about the awkward workings of German grammar, and how I may have understood them much better, if he had been able to explain them.
I am me, I am present, but sometimes, a piece of me dwells in the past.
I skip back, coming up on five years. It is truly amazing how fast time can shimmy by on days when it feels like I have just left his hospice room, just said my last goodbye.
The day that he died, my father and I had planned to go to visit him after I was done with school, but at nine something in the morning, in the middle of my English class, I was taken to the upper school office, and I knew—I knew before I saw my parents faces, and I kept my cool. I think the last time I saw my grandfather was in the hospice, while he was asleep, a few days prior. And it is funny, because I vividly replay so many events, so many things, but it is impossible for me to truly remember my last moments with him, when he was alive. Quite cruel, actually. I remember fantastically our last fight, and my moments with him in the room after he had died—but our last interaction has faded, along with the calm patient man I loved, my grandfather.