Brain Games: Start young or don't start at all

Sciencedaily is good for the blog. In this new study, researchers found that brain training, specifically memory training, works less and less well the older you get. In fact, those who need the benefits the most don't get the benefits of the training hardly at all. Of course, this article is a little hard to read, especially this part:

The results of the study suggest that in order to improve memory, one needs not
only to work hard, but work smart. People in their 60s and 70s used a strategy
of spending most of their time on studying the materials and very little on the
test, and showed large improvements over the testing sessions.
By contrast,
most people in their 80s and older spent very little time studying and instead
spent most of their time on the test. These people did not do well and showed
very little improvement even after two weeks of training.

It reads to me that people in their 80's have no patience for studying. Is that what this means? Or did they have a copy of the test and they kept going over it? Or is this talking about how long each age group took to take the test itself?

Either way, it looks like, if you want to maintain mental health, best start early.