Yes - to add to that, Markdown was based on the ways emails were traditionally formatted. Since breaks at 72-80 characters in that context don't reflect a new paragraph, Markdown helpfully reflows them when converting to a variable line width context. This is actually one of my favorite features of Markdown.

So much so that I wish email clients would treat incoming text emails as Markdown, reflowing and formatting them as needed.

I actually set max-width on Hacker News to 80 characters, so I get this (much easier to read) behavior everywhere. :-)