One way of showing our appreciation for something we’ve received is by passing it on to others. 

This idea is portrayed in the following Talmudic passage:

One day, [Honi] was walking along the road when he saw a certain man planting a carob tree.
Ḥoni said to him: This tree, after how many years will it bear fruit?
The man said to him: It will not produce fruit until seventy years have passed.
Ḥoni said to him: Is it obvious to you that you will live seventy years,
that you expect to benefit from this tree?
He said to him: That man himself found a world full of carob trees.
Just as my ancestors planted for me, I too am planting for my descendants.
 -Talmud, Ta’anit, 23a