I find art to be like basketball. At some point in their life almost everyone wants to play, but in the end only a few are truly talented. But just like basketball, by diligence and work one can be a good player, so can one become a good artist.
On the "what is art" level. I believe art functions on several levels.
It (A) comes directly from the soul. To me, art cannot be a brain thing. Much like writing poetry. Someone can sit around and think and ponder and write a decent poem. But there is a fine line that separates the truly great poems from the 'not-so-great' and that line is the closing of the mind. When the soul is free to express itself without worrying about 'should this color be here?' or 'should I chisel here?' or 'how exactly should the lights go?'
(B) While art is an expression of the inmost being, it has to be refined. What is refined? Have you that since you were a child your writing patterns and styles have improved? As we keep using our skills they become cultivated, they manifest, they mature. That doesn't mean they grow in the same direction as everyone else's for no two people are the same, but there is a sense of maturity that takes place.
(C) Art must be functional. What I mean by this is that art must be able to hold it's own ground without any support behind it. One must be able to be aesthetically, emotionally, spiritually or physically responsive to art without any outside influences being placed in your judgement.
Is art useful in a one-man world. I must say yes. For art is what keeps the soul alive so that the brain may not die. Much like Emily Dickenson's poems that were scrawled on napkins and scraps of paper, her art was in a one man world.. but it was still art none the less, and it gave her comfort.