Basically the point is
When you are successful you think that life is fair. I did the hard work so I have achieved a certain thing. Similarly, when you are lost is a race you think you are not good runner.
This quote encourage you to help others, if you want fulfilment.And that is the theme of this post… that is feel thankful and help others because you are not where you are only because of you hard work, but the credit also goes to the luck that is invisible.