Those who seek happiness anywhere else but inside do not have a clue. Even if somebody says that a brand new Porsche makes him happy, it is actually hormones in the brain that create this wonderful feeling. They may have been released because of an event that happened in the outer world, but that doesn't change the facts.
Of course we need certain things to happen in order to feel good. But once you've understood the dynamics behind it, the trigger becomes secondary. Then you begin to be grateful for the hormones instead of the Porsche. You start to see the beauty in how the body works and rewards you with pleasant emotions sometimes. And finally you understand that buying stuff is by far less rewarding than exercising, meditating or just being around loved ones. This is the magic of minimalism.