In a word... expression. Creativity provides us with a safe outlet to express who we are and how we feel in a way that reveals our authentic self and our innermost feelings.

Suffice to say that most of the creative genuises were those who were willing to really feel their deepest feelings and allowed them to come forth and be expressed in the form of masterpieces. I have a feeling that no real work of art was ever created without real feeling behind it.

For this reason alone I'd say creativity, although maybe not rated as the most practical thing to nurture, is probably one of the most important things we can cultivate if we want to reveal our authentic self... quite a challenge for predominant left brainers like me :))

Just came across this quote and it seemed apt...

Every artist dips his brush in his own soul and paints his own nature into his pictures - Henry Ward Beecher.

I am not an artist. I come up with funny little comics, but can't draw them, so I figure out how to tell it as a joke, when possible. I like to laugh, and funny things will just come to me, and then I have to find a way to communicate that idea to others so that I can feel like I contributed to the joy of others, for both selfish and unselfish reasons. I could do with anonymously spreading a joke just knowing it brightened someone's day, but also, there is ego in there saying, "Look how great I am!"

Also, the process of creating can be relaxing, stimulating, exciting, powerful, etc... While one is in the act of creating their art, they are focussed on the task at hand instead of the worries of life. So, it can be an escape, a happy place, a place of peace and without stress. You can relax and just enjoy being in the moment. I guess in a way, it can be a form of meditation. As I type this, I see musicians, people who make their own clothes or shoes, painters, weavers, writers, etc... not just drawing and painting.

I just watched The Science of Healing with Dr. Esther Sternberg on netflix. She talked about how visually pleasing scenes affect our happiness. Patients with a nice view out the window did better than patients with a view of a brick wall out the window. So, beautiful scenes elicit good feelings, endorphins. I can't speak for artists, as I am not one, but I have heard some say that they have the picture in their mind, then they put it on the canvas, or other medium, and others say they just create as they go. Sometimes memories are called upon to create, and sometimes, you just tap into the collective consciousness and get ideas. The reason to create the vision would be the same as mine and probably more reasons. Art can tell a story, take you somewhere else, create a sense of well being. So, people buy art that elicits feelings that they enjoy. Some art makes you feel repulsed, but some people like that feeling, so they buy it. We watch movies that give us a rush, or make us feel good some way. We listen to music that makes us feel good. All the forms of expressed art can cause feelings, good or bad.

I also have some ideas for inventions, that have yet to be expressed in any form other than in my head and a couple of drawings. Necessity is the mother of invention.

Edit: 10/25/11 I just found this article. I thought you would enjoy the read.

Read Michaela's answer. Art and creativity bring us closer to our true selves which is the source within. When we are creative and love what we are doing we are living in the moment. Living in the moment brings us closer to our source for we are fully present and aware and this gives space for source to create through us. The reason for feeling good when creating is that creating is our natural birthright.

The most important aspects have been laid out in the previous answers, so here just an addition:

"Art and other non-practical creations" are basically about playtime, about engaging in the creative process without the pressure of arriving at a certain result, or doing things in a certain way. We are free to experiment, make "mistakes" and play around with what we've got, find new connections, come to new insights.

But creativity is not limited to what we commonly call "creative", that is art and the like, it is entirely practical, because creativity is the essence of growth and change. Every new thought is a creation, every time we solve a problem we create a new reality. As we create we connect ourselves with the flow, pick up consciously or not what is around us, find our own response and take the world a step further.

In countries where arts & crafts have been reduced or even eliminated from the school curriculum (around 10 to 20 years ago), about 10, 15 years later, when the kids left school and entered professional life, the merits of creativity became obvious: Thinking sideways, learning the process of problem-solving and thinking for oneself, plus developing manual skills. The first area (at least in Germany) where a deficit was noted was not in the "creative" sector, but in the manufacturing and engineering sector. Apprentices and students not only lacked elementary dexterity, they showed also a great deficit in adapting old solutions to new problems. Plus, they showed more anxiety about making mistakes.

Art is indeed self expression in a nutshell, and it can be expressed at any and all level of our own creativity spiritually, emotionally, and physically; but in essence in the work that we do to express it and show to others our own unique talent and gift to share with the world as Art, and as an expression of love for what we do best.