I’ve never had a problem remembering how to use Smalltalk. And I don’t use Smalltalk much; C is my main language. The reason is because there’s hardly any syntax to Smalltalk at all! It’s nearly all message sending: <object> <message>, where <message> can be unary, binary (infix), or keyword (taking on a parameter). That’s it.
Getting back to Smalltalk from C doesn’t take long at all. I would imagine there’s an equal gap between Python and Smalltalk, or Lua and Smalltalk. I used to be a bona fide FORTRAN guru in the 1980s, and this language could hardly be more different from Smalltalk.