A review of the past research into the positive psychological phenomena of the human condition begins this article. The belief that interest and curiosity about the world is a hallmark of childhood experience, as propounded by Maria Montessori, is reviewed noting that a cognitive boon of interest and its motivational power are complemented by the fact that interest feels good. This state of being interested is described further as being characterized by three qualities of enjoyment, being caught up and fascinated, enjoying what one is doing, and being in a state of arousal or excitement. This is contrasted with what happens when the experience of lack or loss of interest occurs, a key feature of boredom or depression. Seeking after cheap thrills may be a result of an inability to create interesting experiences using imagination and learned skills on the part of a young person. These young people were examined in natural settings with the focus being on the young person's experience of interestedness rather than on event being experienced. The Experience Sampling Method, procedures, and measures used in this study are described. Results showed that Bored and Interested groups were discernibly different in terms of global self esteem, an internal locus of control, and a view of the future as hopeful, all associated positively with Interested youth and deemed to be indicators of positive development. Tables provide information on demographic representation of interested groups by percent; analysis of covariance of global self esteem with experience of interest, controlling for race and social class of community; analysis of covariance of locus of control with experience of interest, controlling for race and social class of community; analysis of covariance of optimistic emotions with experience of interest, controlling for race and social class of community; and analysis of pessimistic emotions with experience of interest, controlling for race and social class of community. A list of sources references is included.