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In a study published last year, Ryan Howell, PhD, assistant professor of psychology at San Francisco State University, asked 154 men and women about their recent purchases and found that people who'd spent money on experiences were happier than those who'd bought material goods, regardless of cost or income.

This research bears out a theory known as the hierarchy of needs, developed in the 1940s by psychologist Abraham Maslow. According to Maslow, once human beings have satisfied the basic necessities (food, water, sleep, and shelter), we seek to fulfill more complicated social needs, such as feeling connected to others. "Experiences are more likely than possessions to satisfy in this regard," Howell says.

Consider, too, that we don't judge our memories against other people's as we do our material objects. "If I went to Boston this spring and you went to San Francisco, we'd talk about our trips, but we wouldn't subconsciously be comparing," Howell says. Plus, "we don't get sick of happy memories like we do last year's cell phone model."

So you're all set for that exotic trip. But first things first: do you need a shot?