We are sold on the idea that there are things, people, books, places, pharmaceuticals, clothes, cars, money...ad infinitum - that if we only had this or that or them we would be happy.
Capitalism needs people to buy and consume. We are brainwashed into thinking that having some things equates to being some thing (happy, sexy, smart, powerful...etc.)
None of it's true. We all need the basics food, shelter, security - but beyond that there is no thing that is going to satisfy our basic desire to find meaning and love of self and others.
It's a constant struggle to keep from being overcome by the barrage of selling us things we don't need. For example - whenever I see a commercial on television for a pharmaceutical to make me sleep, or make me happy, I remind myself it's okay to not sleep or not be happy sometimes. In fact if I was always sleeping perfectly or always happy I'd have to ask myself why? We should lose sleep over things and not be happy every so often - it reminds us we are alive.