Once upon a time, there was a very smart scientist named Professor Smith. He was very good at inventing things and loved to explore new ideas. One day, he had a brilliant idea to create a time machine. He worked very hard and finally, he was able to build a time machine that could take him to any point in the past.

Professor Smith was very excited to try out his new invention. He set the date to go back to the time of the dinosaurs. As soon as he arrived, he saw a big, scary T-Rex. He quickly realized that his actions in the past could have a big impact on the present and future. He didn't want to change anything, so he quickly went back to the present.

But when he arrived, he saw that everything had changed. The world was now ruled by dinosaurs and humans were extinct. Professor Smith was shocked and scared. He quickly went back to the past again, this time to the time of the ancient Egyptians. But again, when he returned to the present, everything had changed. The Egyptians were now the most advanced civilization and the world was completely different.

Professor Smith realized that every time he went back in time, he was changing the course of history. He didn't want to cause any more problems, so he decided to destroy the time machine. He knew that he couldn't risk changing the present and future any further.

From that day on, Professor Smith focused on using his intelligence to make the present a better place. He learned that sometimes, it's better to leave the past alone and focus on the present. And that's exactly what he did, becoming known as the greatest scientist of his time.

The end.