[currysausage]

You have to know HTML in order to know where things end. Otherwise, you will see nested paragraphs here:

  <p>Hello <p>World</p>!</p>

when it’s actually two consecutive paragraphs, an exclamation mark outside of any paragraph, and a closing p tag without an opening counterpart.

And when you do know HTML, you might as well omit optional tags.

If you think that HTML syntax is crazy, I won’t blame you, and you might consider XHTML instead, but you should be prepared for different woes.