²⁶A problem with this logic, which we already partly saw in Chapter 11, is that it is not clear why simulation of positive experiences would not cancel the effect of simulating negative experiences. Somehow, it seems that negative experiences are stronger in this case. It is possible that this only holds for some people whose thinking just happens to be more often negative than positive, and it is those people whose mood is most improved by meditation. Or, it could be that due to some evolutionary reasons, this is the case for the vast majority of humans: Baumeister et al. (2001) reviews a great number of results leading to the conclusion that “bad is stronger than good” as far as the emotional effects of life events are concerned. (The important case of rumination was treated in Chapter 11). Interestingly, Plutarch proposed a training method to reduce future-oriented wandering thoughts by recalling good things that have happened to you in the past (On the Tranquillity of the Mind, 14). At the same time, he also recommends cherishing things you have right now, thus making a clear connection to gratitude exercises discussed in Chapter 18. Thus, it seems to be possible to engage in thinking that is not very different from wandering thoughts, but deliberately optimizing the contents can make the effects positive.