Why do we buy art??

Just a thought. I see so many people buying art everyday and spending a lot of money (sometimes up to $200) on a piece of digital art that you can't even have in real life (unless you print it or put it on something (mousepads, mugs, etc.) of course). Do you ever wonder if there's a point in doing that? You could be buying something you can touch or buy something useful in life. I mean once you're older, do you think you'll lose interest in it? One day you might forget about deviantart and your characters and realize that all the money you spent was for nothing? I think about this all the time when I buy. I had a point in life where I stopped going on deviantart and spent time with friends, my (now ex) boyfriend, and worked all the time that I just didn't have time for art anymore. I told myself "buying art is pointless. What will I use it for in the future when I'm married and have kids? It'll just be stored in photobucket and sit there forever". But whenever I see an artist I like that has commissions open I feel the urge to buy and pay hard-earned money. And I get sad sometimes when I pass up the chance. But at the same time I'm kinda glad I didn't waste money. :I No idea how to close this really lol but what are your thoughts on this? Btw I'm not hating on people who buy commissions. I buy art myself. Also my question, what do you guys do with your commissions? What are you going to do with them in the future?