Never Ending Human Desires!

Let's briefly understand about human desires:

Human Desires will never end. Because whatever you can imagine in your lifetime you’ll try to achieve most of them. Let me remember you one day from the past of your life. 
Remember your super excitement and happiness when you bought a new mobile phone which you really need...Now return to this present moment and think of your new desires that you want to fulfil. Just feel how your desire changes with time..
So what I want to highlight is that among all of our desires we should have a super long term and permanent desire, after completion of which you will remain happy for your whole lifetime because that specific desire will going to create an everlasting impact on the society.