Wishful thinking

What is it about human mind that tends to worry about the something or the other all the time? No sooner you get something that you wished for, you start thinking about the next thing you have always wanted. You go ticking the to-do-list mentally. Can the mind ever be contented at what the present has to offer? Is it ok to keep aspiring for one thing or the other? Would you want nothing more once you are a hundred years old. I doubt that. If not something for you, there is always that little something your son/daughter/grand kid wants. You start building castles in air on their behalf as well. The mind is always thinking of an "i wish" thing. I wish we could afford a bigger house. I wish i could buy the new furniture that i saw at the store. I wish i could travel the world for a bit more. I wish my kids would study harder. I wish my grandkid lands his dream job....Even after you are dead, people are trying to fulfill your last wish!