Rosling promotes the value of remaining optimistic about the world we live in and, by extension, suggests that excessively negative attitudes can not only affect an individual's mood but also impede their willingness to take action to correct problems. Although he admits that numerous alarm bells have been sounding regarding the world's situation—including in the area of health, which he knows best—he steadfastly maintains that overall, things are improving for most people.

One aspect of the optimism that Rosling promotes relates to the increasing access to health care that has been ongoing over the last century or more. Yet this is also an area where most people he surveyed tend to be pessimistic. Rosling sees that over-reliance on very general information, as opposed to consulting reliable sources, is a factor that encourages pessimism.

Rosling, a physician and medical researcher, aims to make the reader more familiar with the ways "facts" are created and used. In the research he has conducted about knowledge and how people acquire it, he has come to realize that many people cling to erroneous information. He wants to encourage the reader to learn from factual information but also to take a critical attitude towards it, which includes contextualizing individual facts.

In particular, attitudes toward the “developing” or ”less developed” (often called “Third”) world are shaped by the media. A paradox here is that educated people in the “more developed” world tend to have a flat, rather than nuanced, view of the less-developed countries, lumping them all together and assuming that conditions are uniformly terrible, especially in comparison to their own fortunate lives. While this may improve attitudes toward their own society, it also increases the likelihood that they will dismiss providing assistance to these too-far-gone foreign countries as futile. Examining different factors separately is one way that knowledge can both be accumulated and applied to improving conditions, a process in which optimism plays crucial roles.