What about the "why" behind your "want"? Why do you want that thing, and is there nothing else in the world that will help you achieve the same thing than those specific things you want at this moment in your life? There are things in life you can't change, and learning to adjust your own wants and expectations regarding the things you can't change is going to lead to far less frustration in life.
Feel free to interpret that to mean you shouldn't complain about anything ever, though.