the tortoise and the eagle

Today, I read "The Tortoise and the Eagle", a series of Usborne First Reading, leveled 2 book.

A Tortoise, baking in the sun, wondered aloud what it would be like to fly. An Eagle overhearing her, offered to take her aloft. The Tortoise agreed and the Eagle carried her almost to the clouds, but suddenly let her go. She fell to the ground, dashing her shell to pieces. The Eagle then landed and made a meal of poor Tortoise.

After reading, I thought he didn't notice happy that he had already. From it, I learned I have to notice that and it is important to cherish what I have now.