Okay, kiddo, let me tell you a story about modern Macedonia in Greece.
Once upon a time, a long time ago, there was a place called Macedonia located in the northern part of Greece. This place was the homeland of a powerful ancient civilization, led by a famous king named Alexander the Great.
Many years later, in the 20th century, some people who lived in the same area called themselves Macedonians and claimed they were descendants of that ancient civilization. But other people in Greece disagreed with them and didn't want them to have their own country or be recognized as Macedonians because they thought it'd be confusing with the ancient Macedonian history.
There was a lot of debate and disagreement for many years, but finally, Greece and North Macedonia reached an agreement in 2018 to end the dispute over the name of the country. North Macedonia agreed to add "North" in front of its name to avoid confusion with ancient history, and Greece agreed to recognize it as a separate country with its own identity. And everyone lived happily ever after.