When we understand how the world works, we realize that we owe everything we have to everyone else.
Sure, we earned the "money" to buy the stuff we want, but everyone else produced them and shipped them to our door.
The division of labor is overseen by an "Invisible Hand." We should thank the laborers and the Hand that guides them.
Think of something every day for which you can be grateful.
Maybe something you have that your grandparents didn't.
Or something that a billion other people on earth don't.