...is a lot like writing
There are traditions, things that need to be done a certain way. Even if Grandma isn't exactly sure why things need to be done that way anymore.
There is a tried and true recipe. There's a reason everyone raves about Grandma's cookies.
That being said, if you learn the traditions, if you learn the recipes, if you know them as well as Grandma....then you can start substituting. You can play because you understand the fundamentals.
I mean, not even Grandma's going to bemoan you for swapping the milk in the icing for Bailey's. It's still creamy, still does the job of wetting the icing. But everyone likes a kick of alcohol (even as infinitesimal as in a bit of icing) on Christmas when dealing with family.*
* To clarify, I don't need to get drunk in order to deal with my family. I like them. I'm just...stereotyping.
Also, my Grandma isn't as rigid as this may make her sound. She's cool. And I have high standards, in case you're wondering. If you met my Grandparents, you'd love them. Everyone does.
Are you ready to start playing with the rules of writing? Do you?