Smalltalk is a small language (think C), so you can learn the whole language set in a few days.
The live objects concept might warp your brain a little bit. I've heard lisp does the same, so if you're from a lisp background, you might not find it shocking.
The Pharo environment (IDE) can make all the modern IDEs (Eclipse, Visual Studio) look like babies in diapers.
There is built in versionsing, DVCS, refactoring tool, unit testing framework, The most powerful debugger etc....
You will not regret trying out Smalltalk (maybe you will when you have to go back to C++) :).