Clarifying the purpose of things is a helpful way to find out what is(n't) essential to your day to day workflow, cut costs, and improve productivity.

Young adults especially—upon getting some "disposable income"—may be quick to start accumulating "fun" things, equipment for various hobbies, and so on and so forth. What is the cost of this sort of behavior?

If you are actively involved in doing some activity such as playing the piano, then of course it makes sense to have readily accessible keyboard nearby. No explanation is needed for objects that readily present themselves as useful for the activities you choose to do day-to-day.

What about various "decorations", "hobbies" and other things you may be involved with? Here, I think what sort of living situation you are in is crucial to consider. If you are in a house/place you expect to be in for the forseeable future, then I think it can make sense to have lots of stuff—e.g. specialized seasonal clothing and decorations. These may be items which you use year after year, if only for a month or two out of the year—I don't see any inherent problem with this.

However, if you are fresh out of college (or still attending a university), in a city you don't plan on being in for the "long run", and so on, then I don't think it typically does more harm than good to purchase stuff other than tools and things that will be useful to you daily in an obvious way—like if you play decide to play some videogames sometimes, you may have a gaming console.

The scenario you want to avoid is having to deal with a lot of "stuff" that serves no real purpose to you. Because if you spent a couple thousand dollars over a year on various things and then at the end of the year you have to move and you end up having to throw away most of this stuff, when what have you done really? You've generated more waste in the world through consumerism instead of focusing on quality goods and how to use your time and energy to do useful work for yourself and others.

In the coming days, I'll be working on doing some "cleaning out" of various items—updates will be posted here about how this process itself helps me gain clarity and focus on refining my actions.