It's one of the earliest koans you learn at the temples about being mindful and intentional in each moment of life. The story by Hsu Yan goes something like this:
Originally Posted by Shadiyah
Once, a young monk named Chan was sent forth from the monastery to carry a message to another monastery far away. As he walked through the dense forest, he caught glimpses of orange fur in the dappled shade and heard low growls. Surmising that he was being stalked by a tiger, he quickened his steps, but the large cat easily kept pace with him. Fear gnawed at the young monk, and he began to run blindly through the trees, leaving the path he knew in an attempt to outdistance the hungry cat whose panting breath he could feel upon his neck.
The monk lost his way, and to his terror, found himself at the edge of a great precipice. Behind him, he heard the tiger stop, and begin pacing back and forth among the trees, its golden eyes glinting among the leaves. Shaking, the monk looked down and saw that there were vines clambering over the jagged rocks and he determined to try and climb down them. Just as he swung himself over the cliff, and began clambering down the vines which creaked under his weight, he heard the tiger roar, and saw it stare balefully down at him from above.
From below cane an answering roar, and the monk startled and looked down to see a second tiger, pacing along the stones that lined the bottom of the cliff face, waiting for him to descend.
Shuddering, the young monk closed his eyes and clung to the vine, his only means of support. The sound of nibbling teeth caught his attention and he opened his eyes to see a mouse chewing at the vine that held him suspended between the hungry cats.
Next to the mouse, he saw a flash of red.
A wild strawberry grew in a crevice of the stone, and a lone fruit shone invitingly.
The monk reached out, and plucking the crimson fruit, held it to his nose. The sweet fragrance rushed into his nostrils as the last bit of the vine gave way and the monk began to fall. As he plummeted toward the tiger, the monk popped the strawberry in his mouth, and the flavor was the sweetest thing he had ever experienced.
Imagine what that strawberry would taste like if you knew it was the last experience of your mortal body. You can feel the texture of the seeds on the outside as you gently place it on your tongue and roll it around. You gently bite into it and the sweet juices rush out in an explosion of flavor. Chewing it well and swishing it around your mouth, you notice the alternating tanginess and sweetness before swallowing... yuummmm.... A short transitory moment in life, but yet an eternity. The idea is to enjoy every moment in life like this.