A very easy way of doing this is to constantly exercise our minds. What usually happens with people is that after retirement, we are no longer required to think on our toes as we were while working. Just like our bodies, the mind becomes weak when not exercised constantly. For this reason, you should always find ways to stimulate your mind and keep your memory and cognitive skills up to par. Other ways to maintain a healthy mind include getting adequate rest, eating a balanced diet, doing regular physical activities and avoiding very stressful situations.
When it comes to exercising the mind, there are several ways of doing this that are fun and entertaining as well. For instance, you can take up the hobby of answering crossword puzzles or other cryptic exercises. One of the many perks of retirement is having a lot of time on your hands. Use this time wisely by reading as much as you can. Not only will this entertain you without end, but it will also keep your mind as sharp as it had been twenty or thirty years ago.