> I wonder if you, like me, were also completely thrown when you first encountered a programming language where you didn't also have to enter line numbers...

Haha, yes, totally! For me this was AMOS on the Amiga (a Basic variant). I was so thrown I started by using them anyway as they were supported by the interpreter - it just treated them as labels.

I soon stopped though when I discovered it didn't reorder based on number, so you ended up with

  10 print "world"
  5 print "hello"
  20 goto 5