nostalgia /(?)/

nos·tal·gi·a

nostalgia

n.
  1. Homesickness; esp., a severe and sometimes fatal form of melancholia, due to homesickness. (Med.)
  2. A sentimental yearning to return to an earlier time remembered as happier or more pleasant, or a former place evoking happy memories; a longing to experience again a former happy time; as, a nostalgia for the brotherhood of the Woodstock music festival; a nostalgia for the comradeship of one's college friends.