Turns out that no one really knows what they want. Again, obvious, but let me paraphrase and quote actual studies (isn't it awesome that someone was able to think up a study that proves this?):
Experiment 1 - "Participants in a laboratory study were asked to listen to a pair of very loud, unpleasant noises played through headphones. One noise lasted for eight seconds. The other lasted sixteen. The first eight seconds of the second noise were identical to the first noise, whereas the second eight seconds, while still loud and unpleasant, were not as loud. Later, the participants were told that they would have to listen to one of the noises again, but that they could choose which one. Clearly the second noise is worse - the unpleasantness lasted twice as long. Nonetheless, the overwhelming majority of people chose the second to be repeated."*
They chose the second noise because it was less loud and annoying at the end, and that's all they could remember. Apparently people base their memories on two things: how they felt at the most extreme part of the experience, and how they felt at the end. So in this case, the peak was the same, but the end was less annoying; the second noise was remembered as less uncomfortable overall.
Experiment II: "Each week [college students] had a three-hour seminar with one break that allowed [them] to stretch their legs, use the bathroom, clear their heads, and have something to eat. When the professor asked the students to pick a snack for each of the next three weeks, the students picked a variety, thinking they'd get tired of the same snack every week. In contrast, another group in the same study got to choose their snack every week, and these students, choosing for one week at a time, tended to choose the same thing each week."*
Basically one group had to predict what they would feel like eating and the other only had to decide what they felt like eating at the time. The predictors thought they'd be sick of eating the same thing for three weeks, but we're more creatures of habit than we think we are.
It's starting to look very much like we can't even trust ourselves to make an accurate assessment of the things we prefer! Which means, when we make important decisions, that we're setting ourselves up for disappointment when we come to realize that we're crappy predictors because we have crappy memories and we actually are very unhappy with the thing we chose.
Which also leads to regret. I have been leading to regret for the last three posts and have been neglecting it/putting it off because it's such a hard topic, but I guess the next post in the thread will have it.
*All quotations taken from pp.49-52 of The Paradox of Choice by Barry Schwartz