By "sadness" I refer to the toll that the presidency exacts on the president. One has only to look at the before-and-after pictures of most past presidents to realize the tremendous personal price they each (or at least most of them) pay. Even in the "best case scenario," Mr. Obama will probably look old and gray by the end of his term(s). I recall in a recent interview he gave--I believe it was on "60 Minutes"--in which he stated that he liked to take long, solitary walks and will not be able to do so now.
In Hermann Hesse's Journey to the East, the character Leo comments to the narrator on King David of Israel:
He was also a musician [like the narrator, "H. H."]. When he was quite young he used to play for King Saul and sometimes dispelled his bad moods with music. Later he became a king himself, a great king full of cares, having all sorts of moods and vexations. He wore a crown and conducted wars and all that kind of thing, and he also did many really wicked things and became very famous. But when I think of his life, the most beautiful part of it all is about the young David and his harp playing music to poor Saul, and it seems a pity to me that he later became a king. He was a much happier and better person when he was a musician.