Proof of the Pudding by Robert Sheckley - One man's fact is fantasy for another—except the man whose fantasies become solid facts!

His arms were very tired, but he lifted the chisel and mallet again. He was almost through; only a few more letters and the inscription, cut deeply into the tough granite, would be finished. He rounded out the last period and straightened up, dropping his tools carelessly to the floor of the cave. Proudly he wiped the perspiration from his dirty stubbled face and read what he had written.

I ROSE FROM THE SLIME OF THE PLANET. NAKED AND DEFENSELESS, I FASHIONED TOOLS. I BUILT AND DEMOLISHED, CREATED AND DESTROYED. I CREATED A THING GREATER THAN MYSELF THAT DESTROYED ME. MY NAME IS MAN AND THIS IS MY LAST WORK.

He smiled. What he had written was good. Not literary enough, perhaps, but a fitting tribute to the human race, written by the last man. He glanced at the tools at his feet. Having no further use for them, he dissolved them, and, hungry from his long work, squatted in the rubble of the cave and created a dinner. He stared at the food for a moment, wondering what was lacking; then, sheepishly, created a table and chair, utensils and plates. He was embarrassed. He had forgotten them again.

Although there was no need to rush, he ate hurriedly, noting the odd fact that when he didn't think of anything specific, he always created hamburger, mashed potatoes, peas, bread and ice cream. Habit, he decided. Finished, he made the remnants of the meal disappear, and with them the plates, utensils and table. The chair he retained. Sitting on it, he stared thoughtfully at the inscription. It's fine, he thought, but no human other than myself will ever read it.

It was fairly certain that he was the last man alive on the Earth. The war had been thorough.