Retaining, regaining your mental fitness

Q: Is mental fitness similar to physical fitness in that if you don’t use it you will lose it? What sort of regular mental fitness regime would you recommend for a young man of 84?
A: Mental and physical fitness will both be lost if they are not given constant workouts. On-going activity for both of them is essential for maintaining high levels of both types of fitness. If there is a lapse, it will result in reduced abilities.
If you are a physically active person, and you have ever had a prolonged illness, during which you were unable to exercise, you will have noticed that when you desired to begin your regimen of physical activities you probably experienced some difficulty. It is often taxing to perform the same physical tasks at the same level of difficulty as before. It also usually takes a longer period of time to recover the physical abilities than the time the illness itself lasted. Eventually, if one takes things gradually, the strength returns and the exercise regime can assume the level that was normal for you.
The same deterioration of mental abilities happens to people who do not remain mentally active. It often occurs when retirement comes along. The retiree is so delighted to be able to relax more, that he/she may become a TV-aholic, or pursue other activities that require little critical thinking. This is extremely unfortunate because it is so difficult to start thinking in a rigorous manner once the habit has been lost. In my opinion, much of the loss really is just that of losing the habit of being aware, solving problems, and making the effort to keep the mind working. However, when such inactivity has continued for some time, it becomes very difficult to regain the lost abilities.
To begin a new regime of mental activity, I suggest that you find a challenging type of puzzle or problem that interests you. If you have not been pursuing such activities, try a number of different kinds. Check your newspaper. The comics page usually has two or three types to offer. They are usually quite easy and may often be completed along with your breakfast. If that is the case, of course, you need more to keep you occupied for a longer period of time.
Consider books of puzzles at your favorite bookstore. Some of them contain a variety of puzzle types, while others are devoted to only one type, such as crosswords. Logic problems may take some time to master, but a book of them usually begins with an easy section and works up to those that are more difficult. These require methodical, exact thinking, but give such satisfaction when the correct solution is reached! While you are pursuing these activities, don’t forget to work on your awareness skills, by using all your senses to observe the world around you.
If you look into all these types of problems and ideas, I predict that your mental abilities will grow and that you will find yourself always searching for your next mental challenge.