There's a sense of nostalgia I sometimes get as I walk around maps like Hydlaa and the Dungeon. The music does it too. With the (formerly known as) oja road map, I have a strong sense of nostalgia attached to the music, even though the map it's associated with no longer exists.
I'm not sure how else to describe the feeling. It's like walking through ghosts. It's not an entirely happy feeling, but not entirely sad.
I remember the first time I met Amheh. I remember attacking him many times in a row, dying each time, and how he laughed at the spectacle. I remember meeting Verrliit for the first time, how we talked because my name caught her attention, and inviting her to her first guild. I remember standing around chatting with people while we waited for a special rogue to respawn, how we all worked together to kill it, sharing the broadswords that dropped once in a while. I remember training with the guild knights, dueling Sirunie and five others all at once (and winning against them... until I taught them what I knew). I remember my first guild and guild leader, and I remember meeting my first PS buddy (Hirato).
I guess they're all very simple memories, but they're the foundation of my connection to the game. It's weird that I could have so much nostalgia (or whatever it is) attached to a game, but it's there.