In my mind, the mental process of creating jokes and making others laugh is similar to the processes involved in coming up with an innovative solution to a business or personal problem. The same brain functions, chemical reactions, electrical impulses, even synapses come into play.
Creativity, no matter where it's applied, is the ability to take two or more ideas (that don't seem to belong together) and make them fit together in innovative or surprising ways. Under this assumption, comedy, like any other enterprise, should be accessible for the many, not the few. Just as we study specific subjects in order to apply new techniques represented by our own individual style, we should be able to study humor and emerge humorous.
As with most careers, quantity leads to quality or practice makes perfect. Surgeons practice on cadavers, executives work their way up the corporate ladder, and parents have multiple children whereby the younger ones inevitably fair better, seem cooler and are often times more emotionally equipped than the eldest, who invariably had the distinct disadvantage of growing up with the parent at the same time. The point is, we must take in ideas, mull them around a bit, and then put them to use in order to gauge their efficacy.
One way to exercise your funny bone is to look at cartoons and come up with your own captions. Finding additional strands of humor in any situation invariably leads to developing a good sense of humor - at least that's the goal!
Here's a few examples (my take is written below the comic):
So, if you feel that you suffer from myopia (i.e., the lack of imagination, foresight, or intellectual insight), take stock of all the interests you have. The more varied, the more creative you are. If you only have a few interests, speak only one language and rarely ever leave home, learn how to play the guitar (yes, Guitar Hero counts), pick up a Rosetta Stone at the mall along with a guide book on a country you've always wanted to visit, issue your passport and go see the world from another perspective. Besides returning with photos to post on your Facebook page, you'll be more interesting the next time you have dinner guests and no doubt prepared with a few one liners to be the life of the party!