neighbors moving

Ok, so why do we become sentimental when a neighbor moves?? I mean we were not friends by definition but for the past two years i would say" good morning," "have a good day," "how's Simmy" (her dog) and i could faintly smell her cigarette smoke when she took her ciggie breaks on her porch, it would casually come thru my living room window while my husband & i would watch t.v.(I am not a smoker) We would chat about her halloween & christmas ornaments and have a "competition" her name is Penelope but we secretly called her Penel.
So, day before yesterday i come home and there is a big Budget rent a truck and trailor. Penel casually says she is moving to Oregon. "WHAT?????" we can't believe it. So immediately my daughter and I go to pet Simmy and we take pictures etc... In fact all the neighbor kids come and I take everyone's pictures! I will email to Penel. Anyway it takes her a day to load up (she is older (than me) say maybe late 50's early 60's?? don't know, won't ask!) This morning I hear the big rent a truck start up so I run outside and yup she is really leaving. Don't ask me why tears come streaming down, like i said we were not friends. I guess when you have a neighbor in your life that is pleasant you feel safe. In this crazy world it is nice to have neighbors that don't give you grief and are pleasant and stop for a brief chit chat. It makes for comfort. So as Penel and Simmy drive off I take pictures and wipe my tears! I am going to email her the pics so she knows we cared about her and will miss her.....