hide it under a bushel...no!

Matthew 5:13-16

13"You are the salt of the earth. But if the salt loses its saltiness, how can it be made salty again? It is no longer good for anything, except to be thrown out and trampled by men.

¹⁴"You are the light of the world. A city on a hill cannot be hidden. ¹⁵Neither do people light a lamp and put it under a bowl. Instead they put it on its stand, and it gives light to everyone in the house. ¹⁶In the same way, let your light shine before men, that they may see your good deeds and praise your Father in heaven.

Psalm 119:11

¹¹ I have hidden your word in my heart
that I might not sin against you.

Can someone explain why we don't soak up the word of God like a dry sponge? Is it an unreasonable expectation to have it memorized...at least the New Testament?