I had a weird situation today where I had an old url pop up when looking at my site which I really couldn’t work out. Someone contacted me through an old contact form page from the same url. The reason I knew (and later investigated) was that it come in through an old email contact address.
Google doesn’t “Store” your pages, it just keeps and index of their address.
If you need to Remove a page, you have to delete it from your server with either a ftp app or the file manager in your hosting account Control Panel.