Because philosophy arises from awe, a philosopher is bound in his way to be a lover of myths and poetic fables. Poets and philosophers are alike in being big with wonder.
Nostalgia is a necessary thing, I believe, and a way for all of us to find peace in that which we have accomplished, or even failed to accomplish. At the same time, if nostalgia precipitates actions to return to that fabled, rosy-painted time, particularly in one who believes his life to be a failure, then it is an empty thing, doomed to produce nothing but frustration and an even greater sense of failure.
Natural history is not about producing fables.