Missing Artwork Outside Art Board

It looks like you are opening a pdf instead of an Illustrator document.

Can you describe how you save your files?

Do you save them as .ai, .aic or .pdf?

Where do you save them? Local hard disk, server, dropbox or other cloud synced folder?

Update: I'm not crazy and neither are you if you experienced the same thing and here looking for answers. Some work creeped onto the art board which let me know the right file was opened. These items were clip masked along the perimeter of my artboard, I was hoping if I released them all it would reveal all my notes and explorations I performed outside the art board. It didn't work; only items inside the art board was clip masked. I closed the file without saving hoping if I reopen it the glitch would be lifted; it didn't. What's annoying is I can see my work outside the artboard as a thumbnail in Adobe Illustrator's prompt page under 'recent'. I received a warning saying 'The document contains PDF objects that have been reinterpreted: To get the look, some of the text was converted to paths.' Somewhere in this forum somebody wrote 'PDFs aren't editable and it's best to always save files as AI' but it doesn't explain why this happened. If someone can share how this glitch occured it would help the community understand how to prevent this situation from happening. 

Is there a way I can open the corrupted file bypassing lllustrator reinterpreting my PDF? I hope so but I doubt it. 🤬