Traveling light is a sound piece of advice. For that, you need to leave your belongings behind.
The issue: Suppose you plan to go on a long trip and you stop paying rent, so you have to return the keys. You cannot and do not want to take all your stuff with you, but you don't have that much stuff either and everything fits in 3 or 5 large suitcases. You want to keep all that in a safe place while you travel.
Of course you can think family and friends, but assume they are far away or have no space available. What creative options do you have to solve this problem? Are there places who offer excellent value in storage for your money and charge by the month? Perhaps places that can help you with that even if it is not their main business? Are there non-commercial alternatives?
Location: in principle it could be mostly anywhere, because depending on the price it may be worth the ticket, but preferences would be for Europe, especially some central hub (major cities with huge airports like Paris, Amsterdam, Madrid, Frankfurt etc), followed by Central and South America.
I believe that knowing how to deal with this can be, for many people, a liberating step for finally hitting the road.