The recession wreaked particular havoc on opposite ends of the labor market: on the young and unemployed marooned in their parents' homes for lack of work, and on the (relatively) old and experienced stuck in the workforce for lack of money to retire.

Their problems were clearly not unrelated (particularly in the case of the retirement-aged grocery clerk whose job might have been done by a 19-year-old). But between the two of them, their parallel misfortunes made for a historical anomaly in this latest recession.

You can see it in this chart from the Brookings Institution, which compares the employment rates for different age cohorts in 2000 and 2011 across America's 100 largest metros:

Over the course of the decade, the employment rate for 16-to-19-year-olds fell  from 44 to 24 percent, the lowest it's been in Current Population Survey data going all the way back to 1948.

"It is an astonishing drop," says Martha Ross, a fellow with Brookings' Metropolitan Policy Program who co-authored a recent paper on the recession's abysmal impact on employment prospects for young adults. What really stands out about that graph, though, is what happened to workers over 55. Their employment rates went up over this same time.

"We haven’t seen this before," Ross says, "this combination of employment rates dropping for the younger and prime-age workers while they’re increasing among the workers who are of or near retirement age."

Brookings is calling this a historically unprecedented "great age twist." While every other age group was less likely to be working in 2011 than in 2000 (with unusually bleak prospects for the youngest workers), older people were actually more likely to be working.

In some ways, this may reflect the particular circumstances of a recession rooted in housing collapse: Many retirement-aged workers who had their savings tied up in their homes suddenly needed to stay on the job much longer than they had planned. And the impact of that decision cascades down to younger, less experienced and less educated workers who've had to compete for jobs with the overqualified.

This picture now raises some particularly alarming questions about the workers aged 24 and younger. Studies have suggested that people who are unemployed as young adults later earn less when they are employed. Aging into a crummy economy doesn't just hurt you when you're looking for your first job from your mother's basement; the negative effects persist for years.

Early unemployment, in other words, has lasting scars. And we've just watched an entire cohort come of working age at a time when employment prospects for young workers have been at an unprecedented low.

"It’s not written in stone, and it’s not your destiny," Ross says of the long-term repercussions. "But this is a really formative period in someone’s life."

Young workers without a college degree will have a particularly hard time. But other workers who've been biding their unemployed time in school will have to add massive debt to this equation.

This suggests we should start talking more not about how the recession has hurt young workers, but what it will mean for them for years to come to have entered the job market with such historically bad timing.