If you think student debt is a young person’s problem, think again. A Gallup poll released this week reveals that student debt is the biggest financial worry for Americans aged 18 to 49, above other concerns such as low wages, lack of money, and housing. While more than one in five young Americans (aged 18 to 29) report that they are most worried about college expenses or loans, alarmingly, about one in seven Americans aged 30-49 says the same.After they pass 50, health care takes education’s place as Americans’ greatest financial worry. Indeed, as this poll suggests, adulthood can be divided neatly into two halves; the greatest concern during the first half is the cost of education, and during the second, the cost of one’s failing health. But while it’s not shocking that older Americans are concerned about paying for health care, it’s confounding that so many adults in their 30s and 40s are still fretting over debts they accrued two or three decades ago.This poll seems to suggest that the Sphinx should update her famous riddle: What crawls in the morning, worries about student debt in the afternoon, and frets over hospital bills in the evening?