Imagine your favorite band only played each album in public for a month. Then the songs were sold off to individuals never to be heard again except by those lucky few. To a large degree, this is how the art market operates. It is also why exhibitions are such a special and rarified affair. For a short period of time, we get to see a whole body or series of works by a particular artist. The chance of seeing those works together again is almost zero. This is especially important considering that the artists themselves often create these units of work as a thought process. We are lucky that Miles Davis' "Sketches of Spain" wasn't chopped up and sold off to collectors like we do with art. I can't even think of "In the Wee Small Hours" by Frank Sinatra as separate songs..
For the most part, artwork resides in either the hands of artists or their patrons. If you have bought original artwork, you are a Patron! Art shown in museums or institutional galleries are those special, rarified works that have been donated or purchased for their importance. Even works in the possession of these locations are largely in storage. We the public only see a tiny fraction of art holdings in the world. Art Exhibitions are your unique chance to see something special: a crafted body of expression by a particular artist or group.
Obviously, every exhibition won't be your cup of tea. Just like not everyone loves Nickelback, some artists and styles are going to reflect your tastes better than others. When the time comes that you see something that piques your interest, don't think twice. RSVP for that exhibition. Buy Tickets. Put it on your calendar. Get a sitter. And go experience that once in a lifetime moment.