I'm pretty computer literate and I like the idea of separating presentation and content, but I've yet to find a really great implementation of it. HTML/CSS is a mess, and LaTeX is nice but very difficult to use.
Markdown seems to be the best, but isn't exactly wonderful. I wouldn't ever try to convince everybody I know to use Markdown for everything instead of Word!
This is the reason I use Org-mode. It provides simplicity of formatting like Markdown, but provides enough flexibility to export to format of my choice as needed. (Mainly, when I provide documents to others, I just generate PDF via LaTeX, but other formats including MS Word can be created fairly easily via ODT export.)
Latex is very easy to start with. Just learning a dozen commands will allow you to create many documents. What is a pain is customization, but remember that Latex was created so that only experienced designers would be required to customize a document style.
Markdown seems to be the best, but isn't exactly wonderful. I wouldn't ever try to convince everybody I know to use Markdown for everything instead of Word!