In the novel Manalive by G. K. Chesterton (good grief, that sounds just like how I used to begin my book reports), in the chapter entitled The Round Road (or The Desertion Charge) the author notes that on the corner next to Innocent Smith's house stand a green lamp-post and a red pillar-box. I don't have the foggiest idea what a pillar-box is, and I'm not sure why that little detail stuck in my head, but it did. Now, I loathe it when people ascribe Deep and Symbolic Meaning to everything an author pens, so I won't attempt to say what Chesterton meant with his little detail of the green lamp-post and red pillar-box. But I will say that those two things stand in my mind as symbols of home--of having a place you love not because it is objectively so much better than other places, but because it has your very own green lamp-post and red pillar-box. (You're all going to have that phrase stuck in your heads now, aren't you?)
In his book The Four Loves, C. S. Lewis wrote (there's another classic book report opening for you) that affection is the "lowest" of the four loves (more thoughts on that book here) because the objects of affection are often without any objective merit. We love them simply because they are there, not because they are beautiful or clever or useful or any such thing.
In some ways, though, I think our affection comes very close to how God loves us. He doesn't love us because we are good and holy (if He did, I would be in serious trouble) but simply because we are His.