What creates the feeling.  Does or is there something that can induce the feeling with greater intensity? 

How does this feeling relate to depression or mid life crisis or for woman's menopause(sp)

Music pictures location what effect do each of the have.  with each one pertaining to different since.  are they heighted when someone has a 6 since loss? sight hearing etc.  does the human psychology over compensate and accentuate the feelings.

Ok, here is something to add.  going through a magazine there is an article about the Beatles.  The article was commenting on the infamous "40 Year's Ago today" line from the opening sound of side one of Sergeant Peppers Lonely Hearts Club Band.  The photography was of course the four of them sitting in a row close up and the next two pages were the completed album cover and a b & w of the set and the creator of the set.

The article went through what the artist did in his "vision" of the album cover.  The artist, Peter Blake, based the cover from a list of "70 people we like".  The figures are 98% cardboard and 1% wax and 1% Beatles.

The intention of this description is to present the setting for what I personally got from the article as it relates to the concept of nostalgia.  Peter Blake has without a doubt made an imprint on imagery forever, but it was a very short ride from everyday to infamous.  I am wanting to take just this little example and utilize it as the basis of a "moment of glory" to a life time or sustained period of heightened sensory existence.

Now I am by all means not oblivious of the daily phenomenon of  the rise and fall of celebrities but the everyday existence of people who shape our life's with just a spec of time and notoriety. 

Not to stray from the focus of the two dynamics of the examples here I will focus on the post existence of each and the potential levels of nostalgia