Do it.
Based on your question, you are looking at the visual arts. So, what kind of art are you going to do? do you want to sell work in galleries? If so, do it. but don't commit half way. Be prolific. Don't paint for 4 years and then give up. Because, unless your paintings are Rembrandts (in which case why give up?) your paintings will be worthless in the long run to whomever bought them... or to their children. Antiques roadshow price... $50.00, not $50000.00
So consider at least the people you will interact with, and the contribution you make back to the world. Paintings accrue value because of the longevity and quality of the artist. This is true for the other arts as well. Compete against the world, but more importantly compete against your friends. It raises your skills and qualities. Follow your own vision, because that is the great difference between you and the other guys.
It's other artists that decide what is good art. not galleries or collectors or anyone else. so hang out with your peers. only good things come of it.
Be serious and have fun.
In the great scheme of things, it really doesn't matter what you do, except to you.
Reading these comments, I am reminded by Yoda's sage wisdom. "Do or do not. There is no 'Try'".
For the record, you can do both. It's just harder. Because you should never use one interest as an excuse for poor performance in another.
So do it. It is an entrepreneurial life. Work your ass off and you can become a great success. it is true in any field. The real success comes from those who do the work. And it's a startup world, just like Web 2.0. You can be too far ahead of the curve, or yesterdays news, or provide products the market really likes or miss completely, or come in as a poor second. The art world like silicon valley is very forgiving especially to people who keep on bringing new work for people to experience.
Not many people remember when the Blue Man group were crazy street performers in New York. They worked hard and adapted or tried different things and are now a big success. It's just like a startup. work hard; be adaptive; see what works; do your thing. Sounds kind of familiar doesn't it?