Board Thread:General Discussion/@comment-4821842-20171211025434/@comment-2153169-20171212231228

Personally, I kind of think OUAT's magic is like the Force in Star Wars. It is like everywhere and in everyone, but not everyone is capable of mastering it. Some people have a "gift" and are naturally talented to master it, while some need training for some weak results.

Would explain why some people are able to do magic, while some are not. Also why some people (like Zelena) are naturally good with it, and why all places (including LWM) have magic. Per your origin, your natural abilities, etc... you're capable of using magic in a more effective way than other people.