Like HAML before it, coffeescript is more like 'piglatin with shortcuts' to me, i.e. you have to mentally make a transformation on the javascript you were going to write while simultaneously stripping away unnecessary crud.

This is somewhat analogous to the stage in learning a spoken language where you're mentally translating (rather than just articulating directly in the target language). Unlike a spoken language however, in haml/coffeescript this phase only needs to last about an hour, instead of months or years.

P.S. I have a pet theory that bi-linguals are more 'intuitively comfortable' with what I call 'transformation' languages like HAML and Coffeescript, probably because they're used to cross-compiling their own speech while learning their second language. Not based on any scientific research but it appears to play out in my current office.