why do people always want what they can't have?

sometimes i just wish nothing came down to the cost of things and just relied on trade and trusting among good people. here in the united states that's not how things work, everyone must go to school, and have job in order to survive in this competitive economy we have today. the new inventions and great minds of the world make it so hard not to want what you just cant have unless you have the money for these things. having a job in high school and playing sports can be stressful and very time consuming, so in order to manage my time better in high school with my challenging schedule and time consuming sport i had to quit my job during soccer season which means a cut back on buying. this just so happens to be more difficult than i thought because I'm wanting a lot lately. having lots of thoughts of the future and college i want to try to be ahead of the game by buying stuff ahead of time so i don't have to buy it all at once and have no college fund money when i actually get there. i know this sounds silly but i like to think ahead and be prepared for the distant future. the concept of having a trade system back and just plain kind people to give you what you want and need would be great but cause a fault in our society because people are now used to earning what they buy and paying overly priced prices for things that they want. if only the world would be more conducive to the type of lifestyle i want to live without working to hard for the things that you want or need. but then the probability of me taking care of these things would reduce because in the back of my mind i would know i didn't really work that hard for it and i could just get another one. so having what you always want isn't the best thing for the real world, but i can always dream.