“Even if we were handed everything we wanted, would it really make us sustainably happy?”
Most of us are just looking for the next pleasant hit of anything - the next meal, the next relationship, the next vacation, etc. We stress ourselves out over what we want but do not have yet. However, these thoughts are useless as they do not actually help us in any way, and they keep us from feeling happiness. Engaging only in useful thoughts will allow you to calm your anxious and worrisome mind, and give you a sense of peace and happiness.