Everything about async
It happened when I least expected it.
Someone, somewhere (above me, presumably) made a decision. "From now on", they declared, "all our new stuff must be written in Rust".
So! Rust futures! Easy peasy lemon squeezy. Until it's not. So let's do the easy thing, and then instead of waiting for the hard thing to sneak up on us, we'll go for it intentionally.
I'd like to think that my understanding of "async Rust" has increased over the past year or so. I'm 100% onboard with the basic principle: I would like to handle thousands of concurrent tasks using a handful of threads. That sounds great!