the first thing that hit me when i read the posts in this thread was DEPRESSION. It could be a chemical imbalance/neurotransmitter problems you guys can be having. Not in a sad I wanna slit my wrists kind of way but more like if something great happens to you guys you will remain unphased. We were talking about it in my medical terminology class the other day, if you've been in this state for awhile it's time to look into it.
Depression in that sense might be an option... but what solution would that imply?
Taking it down the neuro science path is an interesting idea indeed. If animals of all kind, down to the reptiles, get afraid, they know exactly three reactions programmed in their cerebellum: escape (procrastinate), attack (nervosity) or freeze (paralysis). The cerebrum, where our main intelligent thinking goes on, is "turned off", thus receives less blood, and we are not that smart anymore.
Non of these reactions is very helpful in our modern society - they lead to unwanted result and reinforce anxiety. But exactly these reactions are basically what I am observing from myself, they are making me feel zombie-like (or reptile-like).
This implies that I absolutely need to figure out what I am afraid of. I'll give it a thought and come back again in the evening (GMT).