hi,
i would see it as a metaphor ,,
it may be related to your present thoughts,in that, are you happy ?,
sometimes we all need to escape back to a time we felt happier,a return to the womb of sorts,
i see these sort of escapes back to the past,as not a retreat from present circumstances,but more a chance to come to terms with true feelings,this sort of comparison with a past experience can release true feelings with the present.
are you longing for something or even someone ,what is your present situation,are you denying yourself anything,these are questions that may bring out the reason for the nostalgia,
these are only my thoughts hope they are of some help,
rgds mikey