One reason to buy original art is that you have something that no one else has. You have a piece of artwork that you appreciate, that speaks to you, that you can almost think of as an extension of yourself. It makes your home more reflective of your tastes and interests. It is a treasure of human uniqueness—yours and the artist's.
Here's a suggestion: find some old art magazines or books to leaf through. Notice what art genres, subject matter, colors and composition appeal to you. And notice what stories the artwork suggests to your mind. Your taste in art may tell you more about yourself.