Stairway To Heaven

Lisa walked up the staircase for weeks until she reached Heaven.
She knocked twice on the door, waited for a moment, and then knocked three more times.
The door creaked open and a bearded man poked his head out.
“What is it?” asked the old man.
“Why?” asked Lisa.
The old man scratched his beard and thought for a moment.
“There was a lot left over from my first project, so I decided to build something with the scraps,” he said, and then he leaned back and closed the door.
Lisa sat on the staircase for a while and pondered.