In reply to David.

Picked up this to comment, because you mention Notepad. I sometimes use a similar text editor to clean up formatted text copied from other sources, like a PDF, and I, of course, expect I can easily paste the result in.

Pasting text from a plain text editor, like Notepad or any, should just work in both classic (text or visual) and Gutenberg. Checked this with Gutenberg and it works perfect. It creates one block per paragraph as when typing directly.

In the sense of text, a block just equals a paragraph. Forget the blocks and the number of them until you need to adjust, rearrange, reformat or change into quote, for example. In text context a block is just the piece of the text that you may want to do something with as a whole.

Visual editor also have "blocks", just not called that. When you want to edit and/or reposition an image, you do that as a block.

When you want to change the level of a heading in classic visual, you need to mark that line(s), making it a kind of "block" for a while. But you have to tell the editor how to treat it as a block, marking the edges of it, before being able to change it, just it and not some extra characters. When it's already a block such is easier and feels more natural.