I'm a bit confused by the if (1..10) statement

This is the bistable operator, take a look at 'range operator' in perlop. Basically in scalar context a..b evaluates to false until condition a is met. Then it evaluates to true until condition b is met. If one of the expressions is constant (as is the case here) an implicit compare with $. (the current line number) takes place.

-- Hofmator