As our population ages, a survey suggests many people are gradually adjusting their views of the so-called “golden years” and retirement. Not too surprisingly, the age we consider “old” gets older as we age, and more than half those surveyed worldwide expect to work in some fashion in retirement.

The median global age will rise from 26 today to 37 in 2050 with broad implications for economies worldwide, according to the United Nations.

Among Americans, this coming era is fraught with anxiety: Only 12 percent said retirement would be the best years of their lives. More than two-thirds (68 percent) said their biggest concern about old age was becoming ill, while 65 percent said they’re afraid of losing their memory. Just more than half were worried they’d be a burden to family, 40 percent said they’re nervous about outliving their money.

Still, defining “old age” appears to be in the age of who’s describing it. For those 39 and younger “old age” starts at 58. But “old age” begins 11 years later than that for people ages 40 to 59. At age 60 or older, “old age” doesn’t come until you turn 74.

Among Americans, 73 percent said a decline in mental or physical ability would define old age, while 48 percent said age was the marker.