i don't rly have anything to put here other than that there are exceptions to everything. laws, social norms, psychology, math (well, maybe not always in math), foreign languages, everything. 

esp in writing! very, very much in writing! proper grammar can be ignored in writing if it's contextual (contextual, not consensual)! all the rules of writing can be ignored if it makes sense in the context of your story, and don't let anyone tell you otherwise.