I'm playing with a new flat-file CMS called Grav, and building a new site with it. I've had my fill of the giant database-driven CMSs like Joomla and WordPress. They're good for what they're good for, but for my dinky little site they're just massive bloatware overkill. I'm looking for simplicity.
Grav is great! Nice little CMS. It's still in beta, so things may change unexpectedly for a while.
I'm very much enjoying writing in Markdown. Makes banging out simple HTML ultra fast and easy, instead of slow and clumsy like the big CMS WYSIWYG editors. Grav takes that Markdown and uses Twig theming to make it look great.
Learning Twig, on the other hand... Wow! A little daunting for sure. I've never been comfortable programming in object-oriented languages, but they're how everything gets done these days, so whattya gonna do? I'll have to get up to speed or die. Oh well... I've learned more difficult things.
On the other hand, I don't absolutely have to learn Twig as long as I don't mind using the stock Antimatter theme (or other themes).