The thing about minimalism is that it's not just an aesthetic, as so many Pinterest boards and inspirational blogs make it out to be. It's the conscious choice to get rid of what doesn't matter so you can make room for what does. Minimalism isn't about just living with one box of things to say you do, or to join some radical hippie movement, or display your cohesiveness as an individual or your self-control or your patronizing outlook on consumerist culture (though it does suck, to be fair).
To be a minimalist is just to realize that we spend our lives consuming things we don't need, and none of it is truly fulfilling. We work jobs so we can buy things to work more to have to pay them off and all for things we don't want and ways we don't want to spend our precious, limited time here. As a newly minted minimalist myself, I am very strongly opinionated on this front: if your space consists of anything but what is useful or meaningful, you're actively holding yourself back. There's no one set amount of "useful" or "meaningful" stuff one "should" have, only that you should be conscious of what takes up your space, and mindful of what purpose it serves. Ultimately, having fewer things does create an overall better existence. Here, a few reasons why:
You Learn To Love What Doesn't Cost Much: Things That Are Purposeful Or Meaningful
Which are the most beautiful things in life. Walking, reading, talking, connecting to people genuinely. The things that don't cost much are the things you loved as a kid, when you were probably happier than you are now. It's a real time wake up call: you cannot buy your happiness, you have to facilitate your happiness, but you can't buy something that will induce it.
You Realize That Things Don't Make You A Different Person
And that's most of why people buy them in the first place. To look different. To seem better. To convince themselves that once they spend so much money on such and such a thing, they'll finally be happy and whole and fulfilled all because they look that way. To realize that things don't make you different is at the same time to begin to focus on what does: where you place your attention and your intention, and how much you open your heart to the people and experiences life offers up.
You Spend Less On Things That Don't Matter To Fund The Ones That Do
You become hyper-conscious of how easily crap can amass in your space, and how much you ultimately spend when you drop a few hundred here and there. Over time, you collect thousands of dollars of things you never wanted in the first place. There are so many different things you could do with that money it's insane. But rather than living, you're just consuming, solely because you think you're "supposed to."
Things Hold Energy Especially The Ones You Buy For Negative Reasons
Now, I am a believer in the fact that things hold actual energy on them, and the things in your space can greatly affect your daily mood just because of that. (Imagine the feeling you get when you step into a space that's dim and cluttered. Yeah. That.) On a more practical level, when you consume and collect things because you feel less-than or because you want to create an image of your life that's different from what it really is or because you just haven't considered how much your physical space is affecting your body and spirit, every time you walk past one of those things, you are reminded of that feeling. Things elicit feelings. They spark memories. They recreate the feelings you had when you got them over and over again (hence the idea of souvenirs). Keep things in your space that you want to fuel your life, not distract you from it.