Can I use the without specifying what object I am talking about? For example, it is well known I can use the if I specify what the object is that I am talking about.
"The boy sitting next to me is annoying."
However, I would like to know if I can still use "The" when the object is only known to the narrator or the person I am describing. For example:
"The sea was beautiful. I shall forever remember the azure sky under which it sat the day I sat by the beach and I met this strange girl with blue hair. Let me tell you a story about..."
Also under which conditions can you use "the" exactly? Most grammar articles are super general and only say it's when the specific object is known, but by whom? There are so many edge cases that such a statement isn't useful.