Most people know the importance of becoming and remaining physically flexible. But surprisingly few people understand the importance of working on their psychological flexibility. Nevertheless, psychological flexibility is very important for staying emotionally fit and mentally nimble. Here are some ways to work on your psychological range of motion.
First, try to keep your mind stimulated by learning something new every day, if possible. It needn't be anything complicated or long. Simply trying to commit a new word, historical date, artist's name, or bit of trivia to memory is great mental exercise that activates parts of the brain's essential structures.
Second, do something differently often. That is, introduce some change in familiar routines. For example, if you're in the habit of sitting in the same place while watching TV, sit in a different place once in a while. If you always hold your coffee cup with your dominant hand, have a cup while using your other hand. By mixing it up like this you again recruit pathways in the brain that are not as active as the ones used by the default behavior thus providing another flexibility stimulus for your mind.
Third, do different things. Instead of doing the "same old, same old" do something different for a change. For instance, have some tea instead of coffee; wear different clothes than usual; hit the stationary bike instead of the elliptical at the gym; order some different dishes when you get take out; etc. This, too, activates and stimulates the brain in novel ways which helps keep the mind and psyche balanced and nimble.