So here's how I find it most easily conceived:
A) You're the unlucky offspring of an incestuous line of blue-bloods, with all the physical and intellectual defects one could reasonably expect. Isolated in shame to protect the family reputation, your barren and lonely childhood leaves you emotionally stunted and depressed. Realizing it's all you have in the world, you zealously cling to your wealth, rejecting any attempted friendships for fear of exploitation. To distract yourself from the multi-layered pain of existing, you seek greater and greater thrills, but ultimately no amount of depravity satisfies you.
B) Fate has dictated you're born into a poor but loving family. Deaf, mute, and afflicted by a terminal illness, your cause serves as a rallying point for your local religious organization. Despite your extreme misery, you're tepid and quiet enough to be very well liked. Before your death, a couple of youths will claim you're an "inspiration", and a respectable sum will be raised in your name for research into your affliction. You'll be well (though modestly) cared for, but that doesn't change the fact that your life will mostly be spent in extreme agony and confusion, confined to a hospital room.
C) You're brilliant, but your health begins to decay before anyone takes notice. Your disease very gradually takes away your mobility, and soon deprives you of any means of communication. You have your thoughts to entertain you, but over the years you grow more and more focused on your misery and less on the mysteries of the universe.
D) You're pitiful and subliminally repulsive to others, but you're barely aware of the outside world. You live in a deeply personal delusion that satisfies you completely.
E) Not too bright, emotionally numb, never can seem to have enough money... High social anxiety and insecurities prevent you from interacting much with others. You have projects but they never really go anywhere: your life is spent entirely in a vague stasis of confusion. On the bright side, you live quite long and never experience any real physical discomfort.