First I was shocked of the AmigaBasic because it didn't depend on line numbers. Before the Amiga I had some experiences in several BASIC-dialects.
(TI-99/4a, ZX-81, VC-20, VC-64, Commodore Plus4)
In the second, I was surprised by the SLOOWWWNESSS of AmigaBasic.
Even my TI-99/4a was faster in interpreting the code.
(And the TI-Basic-Interpreter was the slowest of all pre-Amigas!)