PerCLupi, I have seen you refer to physical illness in earlier posts.  Being ill can make one feel much older than one's years.  It can also leave one depressed.

I am 65 years old and my poor body shows the wear, arthritis, a resection of the colon, loss of the right lower lobe of my lung, etc.  I can still do some physical labor.  My memory is still intact, so far as I can tell, but the recall time has gotten  longer and less reliable, especially for recent memories. My mood has improved since I moved from L.A. to northern Arkansas.

I very much like your idea, my problem being my own incompetence in the three or four other languages of which I have a smattering.  The works of our common heritage I know almost exclusively in translation.  I suppose I could propose translations for inclusion.  I have seen you reference Sanskrit in some of your linguistic comments.  

I would suggest that the Vedas are a part of our common Indo-European Heritage. In that vein I will propose inclusion of the Swami Prabhavananda/Fredrick Manchester translation of The Upanishads, especially the Katha Upanishad.  My own copy is an old  paperback Mentor Classic.  I have often found it to be a balm to my soul.  

"It is not necessary to have hope in order to persevere."