Magic

In ancient history when the northern Europeans and, later, the Romans invaded the British Isles they would have noticed that the Celtic people who originally lived there were a lot shorter than themselves.
I assume that’s why they called the Celts ‘little people.’
And they also had lighter skin (even the Norse people didn’t have freckles) so they called them ‘fair folk.’
And those Celtic people probably used methods similar to those used by Native Americans to hide themselves, such as erasing their own footprints. Those may have seemed like magic to the others.
I think that’s how the legends of fairies may have originated.
Of course if any of the people who lived back then, or even hundreds of years later, were to see what we can do today with modern technology, they would be sure we live in a magical world.
Even people who died in the 1960s would have been be amazed if they could have seen what the world is like today.
Although we’re kept apart from other people so much because of covid, we have a lot to be thankful for, magic or not.