Like in any reasonable language (see Free Pascal). If you have 5 apples, the last apple is the 5th or the 4th? Think about it.
Yeah but why restrict yourself to using 65535 possible values of an integer while you could have 65536?! :P
Seriously though, I guess it really depends on what you're used to. I'm mainly a c++ chap and I find it a really annoying pain in the butt to keep in mind lua starts to count from 1.
And eww, it uses ~= instead of != for inequality. That bugs me.
Which is especially annoying if you got an azerty keyboard like me. Fun fact: To get a ~, you have to actually press ~
twice (which is done by pressing alt gr + a button next to right shift, so you gotta move both hands real far) and then backspace to remove the one it typed too much.
Most reasonable languages (see Pascal or Ruby) use keywords. I don't know what idiot came up with the curly braces idea ;).
It's not that idiotic... it looks less messy to me that way... again, though, they're a pain in the butt to type with azerty, because they're another goddamned alt gr combination.
(Curse you, France! Cuuuuurse youuuuuu!)