Here’s a puzzle for you.

Despite their painfully high student debt burdens, elevated unemployment rates, greater likelihood of living with their parents and their general failure to launch, millennials turn out to be significantly more economically optimistic than their elders.

The chart above shows data from the Conference Board’s monthly consumer confidence index. As you can see, younger Americans usually hold more positive views about the economy than their older counterparts do, but the gap has widened significantly in recent years. In newly released data for June, the spread in confidence readings between the young and the old was a whopping 58.8 points.

That’s the widest gap ever recorded.

Why? One possibility is that the composition of respondents in the different survey groups has changed over time. Note that the survey groups are sorted by age of head of household. In recent years, living with your parents has become more common and less stigmatized; perhaps this means that the shrinking group of young people that still opts to live on their own — i.e., to head their own households — has become increasingly better off relative to peers.

By the way, it’s worth noting that around the world, the young tend to be more hopeful than their elders about the current and future state of the economy.