As a minor point of connect, yes -- no matter what I look like, I see the beauty and life in the face of death, and I see the pall of death upon that which is alive. I see it all at once, I can't separate it or stay in the Now. I see someone in front of me, I can simultaneously see them at their decline as well as in their youth. It's all the same to me, and it stirs up a mix of feelings.
Just watched Pan's Labyrinth again over the weekend with my son, and that movies really captures a lot of that feeling for me... ephemerality of life, and what a beautiful and tragic thing that is. That whole concept is only accentuated with existential awareness, which suggests that there is no real eternity where life continues, that death is the end, and yet life and one's existence is even more beautiful because of its fragile, temporary nature.
I would like to say that I disagree with some of the rest, since I find sadness in this vein beautiful and moving... but your comments about masochism might have some truth in them -- the pain and push/pull of opposing emotions for some reason feels pleasurable on some level.