Desire things.

We are social beings. As we are born, we are feeded with things . Every other person gets us gifts, goodies. So our first understanding is that THINGS makes us happy.

As we grow , more complicated things attract us, and our happiness depends on bigger goals and achievements.

But things have a life they born, and they die. They have limited happiness parameters, after sometimes it whether off.

This understanding is good for spiritual growth.