The more you carry, the slower you go.
Everything you own owns a piece of you. You have to store it, protect it, clean it, catalog it, track it, walk around it, sort through it, move it, and occasionally replace it. Put simply, owning stuff is a lot of work. If the “stuff” in question is useful, if it drives your goals and makes you a better person, then it just might be worth it. Sadly, even those of us that recognize this can easily find ourselves to be the victim of our own acquisitiveness.
The problem is that it takes energy to acquire stuff. No one wants to waste that effort, and they want even less to have to repeat it. And so, in the fear of having to return to the store and buy another Hawaiian flowerdy shirt, we keep the same one we haven’t worn for 5 years in our closet. Never know when we might need it, right?
One must maintain a balance between preparedness, and hoarding. As with most things in life, hard and fast rules on minimalism (have no more than x of y) will almost immediately come up short. Some judgment is required. The only sure thing is that repeated and regular review tends to push you in the right direction. You have to make a habit of noticing an item you don’t actually use and asking yourself if it is really worth more to you than its value as a donation tax exemption.
If you pared your world down to the items you actually use, how much space would you really need?