But then there are the other times. The times when I make myself do things that I don't want to do, and then I'm like, "Oh my god, why did I do that? I didn't even want to! I expected it to be horrible, and it WAS horrible. It was absolutely horrible."
And I don't really know how to tell the difference, beforehand, between those two situations. I think that's because there are so many factors involved in whether I consider something "worthwhile." The first is rationalization. Sometimes something is genuinely terrible but my mind, somehow, rationalizes that thing as a learning experience and makes me retroactively glad that I did it. The mind is sneaky that way. The second is expected result. If the thing I'm doing is something like applying for something competitive and I don't end up winning, then of course it feels like a waste of time. However, that doesn't necessarily mean that it actually was a waste, since, beforehand, I couldn't have known that I'd fail.
So the easy thing to do is to generalize and say that I should just do the things I don't want to do.
But that's a stupid heuristic that's meant for people who aren't very self-aware, and I feel like I ought to be able to do better than that.
Generally speaking, when I don't want to do something, it boils down to a fear of the unknown. I don't know what the experience will be like. The good parts of it are unknown, and, hence, unvisualizable. However, the bad parts--the travel, the tiredness, the wasted time--are relatively easy to visualize. In these cases, it seems best to err on the side of doing, rather than not doing. I mean, I should do the thing in question at least once, if only to clear up the unknown and figure out whether it's really that bad.
As a simple example, when I go to a new part of SF, I'm sometimes tempted to take public transport--even though the transit time is often longer than driving--just because I'm afraid that I won't be able to find parking. But instead I usually force myself to drive, because I know that oftentimes the parking situation is not as bad as I fear it will be (although sometimes, as in the case of the Lower Haight, it's worse than I can imagine).
On the other hand, I sometimes find myself forcing myself to do things I don't want to do, simply because it feels like something I'm supposed to do, or something that I somehow committed myself to doing. The desire to do the thing is not an organic one: it doesn't spring from my natural inclinations; instead, it feels imposed upon me by society. I usually only realize this in retrospect, when I decide not to do the thing and experience no regret about it.
For instance, I could've taken a third year at Hopkins and stayed on to teach. It seemed like the right, safe, natural thing to do. Easy money, doing something I already knew how to do. But I really didn't want to, so I didn't.
I think sometimes it's easy to feel railroaded into doing something, simply because not doing it will require speaking up in some way. In these cases, there's a creeping uneasiness that I try to extinguish.
Maybe instead of being "Do the things that you don't want to do," the heuristic should be, "If you feel obligated to do something, but you don't want to do it, then don't do it (if possible), but if you aren't obligated to do something, and you don't want to do it, then you probably should."
The difference, emotionally, is the difference between fear and dread. If I don't know how unpleasant something is going to be, then I fear it, but if I know exactly how unpleasant it'll be, then I dread it. And whereas fear of the unknown should be ignored, dread is something that I should listen to.