When you move, you clean. Generally a home only looks as clean twice. When you move in, and when you leave. When you see the place, now emptied and as spotless as can be, it's not ghosts, nor anything supernatural, simply the knowledge that days earlier, your stuff was there. Weeks earlier, your entire existence was there. You were watching movies, fucking, sleeping, crying, jerking off, talking to friends, hanging out, drinking beer, cleaning when you felt like it, and dealing with occasional problems (in my case a basement that had drainage issues that were covered by my policy, but just the same). A place covered in your stuff, your things, your odor. The innate knowledge of its space, when to duck your head, where you put your glasses in relationship to the bed, where you stashed things. Every place you stay, you learn these rules. How things work to work, the quaint failings, especially if like me you've mostly lived in places that had some mileage before you got there (I lived in a new apartment for a couple months in college until my roommate got us kicked out on a noise complaint). Now I also worry about my cat, where she likes to stay, what her favorite nooks and sleeping places are. What she likes to play with.
And when you do the last walk through, not out of nostalgia so much as making sure you haven't left anything behind, nostalgia has a habit of creeping in. Fewer things in life feel as definitively end chapterish as moving.