³⁴(Poerio et al., 2015). Intriguingly, the effect of wandering thoughts on mood may strongly depend on whether you think about the past or the future. Ruby et al. (2013) found that future-oriented thinking has a general positive effect on mood, even if the contents were negative; perhaps this is so because when we solve a planning problem, we get happier. In contrast, thinking about past events was found to lead to negative mood independently of the contents of the thoughts.