Ok, so there was confusion on what you meant by zero-sum there, so I'll grant you that the now/then part of my counterargument doesn't apply. However, I still maintain that your definition of zero-sum (one person's positive can only come by someone else's negative) results in ludicrous results in some cases: let's look at 9/11 for a moment, in this perspective, shall we? Ignoring the loss of happiness of all those who were actually killed (or assuming that they balanced each other out in terms of happiness), do you really think that the emotional gains of the terrorist cells (which is a very small subset of the population, no matter how you slice it) equaled the emotional losses of the family and friends of those who died? Of the American populace that was devastated, even if they didn't know anyone who was killed? Of the world at large? Because I'm pretty sure that would require each person who actually supported 9/11 to reach unimaginable heights of happiness to maintain that zero-sum game you believe in.

I'm not going to pretend I understand what you're trying to say in your second paragraph.

So, because you enjoy whatever someone else does, that makes you likeable? Personally, I find that lack of commitment to your beliefs to be incredibly unnerving. I like being around people who have the self-confidence to say that they dislike something that I adore, as long as they have a reason for it. If they're willing to discuss things, so much the better. I've had some wonderful conversations with very good friends based purely on the fact that I dislike religion as a whole, while they are devoutly religious, for one simple reason: I have reasons that I dislike religion, and I can make a reasonable argument, even if it can't convince others (and I don't try to convince others, it's an individual choice, imo).

Being there for people is something that I've always prided myself on, but I also recognize that there are times/reasons that I can't be - so I apologize, wish them luck, and we continue being friends.

Why would you want to change that you don't want anything for yourself? Because you can't tell me that having no motivation is actually a positive thing, in any way, shape, or form. For yourself, or for anyone else. I'm sorry, but you can't.

Obviously, only you can decide if not dating or making yourself available to meet someone is fine for you; just don't think that just because you aren't dating someone means they can't be dependent on you for happiness, at some level. As I said earlier, my mood generally tends towards where my friends are - if they're in a good mood, it puts me in a better mood; if they're feeling sad/sick/out of it, I'll be in a worse mood. Not because I'm dependent on them for happiness, but because I care about whether or not they're happy - and if they aren't, it makes me sad.