One thing in Rust I find very neat is std::borrow::Cow, so I blogged about it: Holy std::borrow::Cow. That got a good number of great replies on reddit, so I blogged a Redux, which should read a bit like a detective story uncovering String's secret identity.
I had a lot of fun writing this, so if there is interest, I may resume the detective story to uncover more "shady" secrets about Rust. The tentative project name for this is "RSI: Rust Special Investigators".
So I'm asking for mysteries to be solved. What things in Rust always leaves you scratching your head?
Also does someone want to join the fun? We could have multiple investigators solving mysteries together!