Now there's more evidence these brain stimulating activities at any age help to preserve memory.
Rush University Medical Center researchers studied about 300 people over six years.
They tested their memory and thinking skills and even took a closer look at their brains after they died.
Those participating in mentally stimulating activities both early and late in life had a slower rate of memory decline.
Doctors at the Cleveland Clinic are not surprised.
"The more you do the better off you're going to be and the earlier you start this, you're probably going to get more benefit because the benefit was shown starting from childhood through middle-age, late-adulthood, even older-age, everyone got benefit from this," said Dr. Ronan Factora, Cleveland Clinic.
There's more on this finding in the journal Neurology.