Ahh.... I can't find the word on dictionary.com, but this is the closest http://dictionary.reference.com/browse/nostalgia
if you dont get their definition, here's mine :D
A fondness feeling when you think of the good times of your past. Most of the time, not all the time, you get this feeling you get when you think of the good times of your childhood, or you're homesick. Sorry, I'm bad at explaining. Hope this helps! :(
edit: I believe you mean nostalgia by this definition.