It may help you to consider that there is no such thing as a "25 x 25 array" in Perl. Of course, we can simulate it with a structure called an "array of array refs" (AoA for short). The subscript notation that you use (documented as an alternate way to dereference a reference)hides this from a casual reader of our code. This works so well that we all tend to ignore the difference. "use strict; is your friend because it lets us know when we forget the subtle difference and accidently create symbolic references.