Psychologists know that “secure attachments”—close, positive relationships such as healthy marriages and good friendships—increase our interest in new experiences. Babies who have learned they can count on their moms, for example, tend to try unfamiliar toys in a lab more readily than do babies whose insecure attachment to caregivers makes them anxious and clingy. A recent set of studies published in Personality and Social Psychology Bulletin reveals a surprising explanation for this attachment-exploration link: feeling alive and full of energy.

Research participants who recalled a close positive relationship from their lives were later more willing to opt for novel activities like foreign travel—and to report heightened vitality—than participants who had thought about a negative relationship or even a sitcom character. “In insecure relationships, people have to resolve negative emotions because their needs haven't been met, and having to do that can be emotionally draining,” explains lead author Michelle Luke of the University of Southampton in England.

That energy drain leaves you with low vitality; exploring unfamiliar territory feels like it would be overwhelming. Thinking about a good relationship, on the other hand, may give you an energy boost for trying new things.