Answer with Explanation:
The speaker depicts the Americans as unable to cherish the beautiful moments because they are always in a hurry to think about what other things they can accomplish due to short time. This shows their materialistic side that once they achieve one thing, they relax and, in just a moment, they become violent again to get more than they achieved.
They always want to achieve things easily without thinking about the consequences of their actions on others because they want to be easily gratified. They are not immediately contented nor do they find things perfect for their satisfaction. Thus, they are always restless and anxious and it makes them unhappy even if they have the abundance of things.