Okay, kiddo, so John Barbour was a man who lived a long, long time ago in Scotland. He was really special because he wrote a type of poem called an epic poem.
An epic poem is like a really, really long story that's told in poetry. It's kind of like a song, but instead of just singing it, you say the words in a special way that makes them sound really cool. John Barbour's most famous epic poem was called "The Brus" and it was all about a man named Robert the Bruce who was a very important person in Scotland.
Now, the reason why John Barbour was so cool was because he was one of the very first people to write an epic poem in the Scottish language. At that time, most people wrote poems in either Latin or French, so he was doing something really different and special.
His poems were really fun to listen to and were full of action and adventure, just like your favorite stories! Plus, he helped to make the Scottish language more important and respected, which is really cool too!