A person can make himself happy, or miserable, regardless of what is actually happening 'outside,' just by changing the contents of consciousness.
Mihaly CsikszentmihalyiFew things are sadder than encountering a person who knows exactly what he should do, yet cannot muster enough energy to do it. "He who desires but acts not," wrote Blake with his accustomed vigor, "Breeds pestilence.
Mihaly CsikszentmihalyiAnd, in fact, you can find that the lack of basic resources, material resources, contributes to unhappiness, but the increase in material resources do not increase happiness.
Mihaly Csikszentmihalyi