We often are ungrateful and if we look closely, we are blessed with so many things for free, be it free oxygen, water when we are thirsty, opportunities to work and earn money and the possibility to buy good foods and experience this universe. I guess it's human nature to forget importance of stuffs which are available without asking

That is life for you, people don't always appreciate the little they have. Human have that nature of not being grateful, but I pray we should learn to get the attitude to be grateful with everything we have around us.
It can sometimes prove to be counterproductive to be satisfied with whatever we have, because if our greed and desire just cease to exist, we will not make any technological or any type of advancements. But yeah, somewhere between being content and having the desire there should be a line of balance
