Youth is when you're allowed to stay up late on New Year's Eve. Middle age is when you're forced to.

Our fMRI scanning reveals that middle age represents the transition between the patterns observed in youth to that found in old age. The seesaw imbalance in the two frontal lobe areas is not as significant as in older adults, but the functional changes are detectable by middle age.

Middle age went by while I was mourning for my lost youth.

The three ages of man: youth, middle age and 'my word you do look well'.

There are three periods in life: youth, middle age and 'how well you look'.

The perceptions of middle age have their own luminosity.