From a FastCompany.com article, The Science of Why You Should Spend Your Money on Experiences, Not Things: 

There’s a very logical assumption that most people make when spending their money: that because a physical object will last longer, it will make us happier for a longer time than a one-off experience like a concert or vacation. According to recent research, it turns out that assumption is completely wrong.

“One of the enemies of happiness is adaptation,” says Dr. Thomas Gilovich, a psychology professor at Cornell University who has been studying the question of money and happiness for over two decades. “We buy things to make us happy, and we succeed. But only for a while. New things are exciting to us at first, but then we adapt to them.”

There have been things in my life, whether they’re still in my life now or not, that still glow in my memory for the happiness they sparked. But it’s true for me that unique experiences endure and resonate far more vividly.

My summer abroad in college was a singularly great adventure that even now is satisfying to recall. Vacations and shows and fun family outings, even trips to the local movie theater, continue to be sources of joy long after they happened.

Apparently, even unpleasant experiences have value:

One study conducted by Gilovich even showed that if people have an experience they say negatively impacted their happiness, once they have the chance to talk about it, their assessment of that experience goes up. Gilovich attributes this to the fact that something that might have been stressful or scary in the past can become a funny story to tell at a party or be looked back on as an invaluable character-building experience.

This is a great reminder to live my life. To fill my days with experiences worth remembering, not things that will be forgotten.