There are both gains and losses in function. To overcome this decline, break learning sessions into shorter segments. There is no change in how much we know. In fact, the longer we live, the more we know. Problem-solving skills improve with age.
Concentration is harder with aging.
Try working for shorter times and take breaks more often. Loss of depth perception in the aging brain may affect driving. Memory for proper names deceases. Language skills that include grammar and understanding are not affected. Memory may increase.