Actually Vik, I don't think you lack empathy at all. You might not have it developed to the same extent as people who make use of it in a professional setting but based on some of the answers/scenarios you described I think it's there.
What you seem to lack is sympathy, which is not necessarily a dysfunctional thing.
It is theorized that there are two kinds of empathy, cognitive and affective. Cognitive empathy is the ability to recognize emotions in others. Affective empathy is the emotional response to them. I have some of the former, probably none of the latter. I can recognize that you are sad, for example, but if I have an emotional response, it will probably be annoyance or irritation. Usually I simply want to fix whatever the problem is and move on. Sometimes I can, more often my friends and family get annoyed with me when I can't demonstrate any long term or deep connection.
If you have been sad, then you know what it is like to feel sad. Therefore, your ecognize ssandess in others. That's empathy.
Sympathy is 'doing something abut it'.
See what I said above. Moreover, I can't entirely relate to other's emotions. I have tried to examine my emotions and reactions more closely over the past few years, having escaped some rather unpleasant circumstances and now having the breathing room to do so. Some things I do not appear to experience.
For example, I don't appear to feel guilt. I can regret doing an action because it has bad consequences for me, or I can fear getting caught, but I have no intrinsic bad feeling for certain actions. I have to use the word "bad feeling", because that's what it has been described to me as. This doesn't mean that I run out and start murdering people - there are many good reasons not to kill people aside from anticipated bad feelings. But I certainly don't feel bad about wanting some people to die, or for taking actions which were "mean" but also legal. This is but one example - for example, I don't ever recall feeling grief. Can I feel angry that someone was taken away from me? Yes, for a few minutes. Can I miss seeing them now and then, because I found them interesting? Yes, absolutely. Do I feel the "deep, enduring sense of loss" that others speak of and demonstrate? No. Never. Not once.
And I sometimes feel emotions with no reason, or, perhaps, odd emotions. Fortunately, I don't think that I experience very strong emotions most (if not all) of the time.
I can't help but pity you then. That actually sounds like it really, really sucks.
Seriously, working in a soup kitchen does nothing for your emotional well-being? What about volunteering some of your spaceship time in exchange for the Big Brother program, where you can give a troubled or hapless kid an afternoon of enjoyment and discussion that he might not otherwise get? What about simply holding a door open for an elderly woman as she smiles and thanks you?
Wouldn't these things make you feel good? Even just a bit?
If not, are you a zombie or just totally depressed?
Of course it does nothing for me. I really don't understand why it would do something for me. There is nothing about feeding soup to bums that would appeal to me. As for the Big Brother program, while I might enjoy discussing things with an intelligent kid, I don't find most kids to be such, and I certainly have more entertaining things to do with my time.
I actually have tried doing things like this, now and then, just because of how others talk about them. The only thing I feel is disappointment, or, if I gave up something I wanted, loss. When I was a teen, as a Christian, I used to do 5-day clubs (like Vacation Bible School) for kids. Honestly, I found it a chore. I've tried visiting nursing homes, giving to the homeless, and many other things. In general, I find it either unpleasant or incredibly boring. In fact, until I understood that others can actually feel a connection with someone else's happiness, I couldn't understand any reason for these actions aside from religious or social duty (you know, the "give to the poor or you'll burn in hell" sort of thing, common at my former church).
And no, I'm not unhappy. Actually, I feel relatively happy and unstressed most of the time. Physically, my work can be stressful, but I don't lose sleep over just about anything, work-related or not.
And I do have my own means of being nice. I really enjoy Kiva loans, for example. I don't care about the people I loan to, I just enjoy the feeling of success and, well, pride I get when a loan is paid back and I can lend again. Sure, it's not all that amazing, but it feels like I made a wise investment decision, and that's very satisfying. So, people in poverty get a leg up, and I get to feel good. Everyone wins. And that, too, makes me feel good, because it means that I found a way to get selfish pleasure out of of a charitable activity. I'm fucking awesome, thank you.
I also just like doing occasional random benevolent things simply because I enjoy manipulating people. I especially enjoy manipulating people in constructive ways. In my opinion, any idiot can tear things down, but only a smart or cunning person can build them up. Right now I have a little scheme going with an older, shy Japanese woman who lives a few doors down from me. I think she is lonely, but I can't be sure, because, you know, no empathy. Anyway, after being introduced to her by a third person who hoped I could fix her printer (I couldn't), I decided to start bring her a little something every week. Usually it's something like a small pie, a loaf of zucchini bread, cookies, or whatnot.
I don't really care for her one way or another (actually, sometimes I have to try not to feel a little contempt, an emotion that I find too common in my make-up), and I certainly don't have any designs on her (she's older, as I said), but I find her increasing delighted bewilderment to be tremendously entertaining as she continually tries to assure me that I don't have to bring her stuff while also very much enjoying it and telling me that she likes the presents as well.
I get to feel mischievous, manipulative, and a bit like a tiny benevolent god, and she gets to feel that someone is showing her a little care (even if it's an illusion), and, also, pie.
Is this wrong? Is this right? Honestly, I don't really care. I enjoy it, so I do it, and it hurts no one, so I'm not going to get in trouble.
People fake a lot of human interactions, but I feel like I fake them all, and I fake them very well, that's my burden, I guess.
I have an ability or a sickness. I am able to be selectively compassionate - I have the full suite of emotional reactions but if being compassionate puts me or mine in danger then I have the ability to step over someone's bleeding body rather than get involved.
It's not fear that paralyses me from doing what I want - help a hurting human being. It's a conscious triage decision. Sometimes I hate that I do it, but it never changes my reaction.
I mostly don't like Dexter. Just because I can't connect with others emotionally does not mean that I have some great desire to run around killing people. I also do like Dexter, a little bit, because it is sometimes an interesting show. Yet, just because many reactions are faked, doesn't mean that I'm a homicidal maniac. Seriously.
As to the rest of your post, I think that that is a skill, and a useful one to have. If you have the full suite of emotions, but can set them aside when necessary, then you have the best of both worlds, don't you? Do you work in a trauma or emergency-related occupation, by any chance?