http://revach.net/article.php?id=4380

Section: Stories   Category: Mashal
Rav Chaim Kanievsky - A Big Fish In A Small Aqaurium
A person did a little experiment in his home fish tank and then ran to Rav Chaim Kanievsky to question the results.  Chazal in their famous Mashal, tell us that although fish live in an endless body of water, when the raindrops fall they all rush to the water's surface to catch the drops of water.  While this seems absurd on their part, Chazal tell us the Nimshal is that water is like Torah.  No matter how much Torah one possesses within them, when there is an opportunity for more, it is natural for us to run to catch every single drop.

However this man's experiment didn't yield the same results.  When he sprinkled food into his aquarium all the fish came running.  But when he poured drops of water, the fish didn't budge.   Why not?  It couldn't be that the rain is sweet water while the ocean is salty, whereas the fish in the aquarium have all the sweet water they need, because that would disprove the point of the gemara.  So what went wrong?

Rav Chaim explained as follows.  In the ocean the fish lives in boundless water which stretches on indefinitely around the entire world.  The fish learns to appreciate this water.  He knows the value of a drop of water.  In the aquarium, the fish is trapped in a tiny area of water.  He doesn't learn to appreciate water, water is not the only thing in the universe and maybe he doesn't even think it is so vital.  Another drop or two means nothing to him.

The nimshal is that those who live in a sea of Torah, have a unique appreciation for every additional drop.  They jump to hear every vort, every small halacha, every mussar thought.  The rest of us casual learners, whose lives have a very finite and limited dose of Torah among the many other activities that we hold dear to us, do not flinch just because another drop or two becomes available to us.