In my experience, the gulf between not understanding programming and any beginner language - say, Scratch - is much wider than the gap between any two languages in the same family.

Java is a terrible language to teach early programming: the features chosen to get to OOP get in the way of understanding basic control. Perl is better. Python is miles better. A dialect of Python with more explicit blocking instead of whitespace sensitivity would be excellent.

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As for constructing a toy system with the plan to throw it away after you've learned from it -- isn't that what an MVP is?