I'd get some time to learn and write some assembly and when I'd get a break again the chips changed and there were 20+ new things to learn or the code wouldn't be as good as compiled C on the new compilers. What little I can't do with C on these ATMELs, I probably don't want to do on these ATMELs.Whatever the language, what you want to learn is organization, flow and logic.
amforth needs approx. 8KB Flash memory, 80 bytes EEPROM and approx 200 bytes RAM for the core system (including the compiler words).
The dictionary is located in the flash memory. The built-in compiler extends it directly.