I was lucky to do some Smalltalk back at Uni and all the "message passing" idea as opposed to "calling methods" was mind blowing.
Unfortunately the VM idea didn't run super fast and we didn't see real utility. I mean, the windows system and the IDE were very awkward even for the time with Win95 setting the "standard" (although I was using Linux and IceWM back then, I never used Win95 at home).
Yet, it was a nice experience and I have good memories of making simple GUI apps.