Well I think the thing is that you invoke printGoodBye as subroutine with no argument, so in your example nothing should be printed

If you would for some reason put

printGoodBye(@_); # instead
[download]

you would see the HASH-stuff

However I think that in order for inheritance to work, the "hash" or instance or ... needs to be BLESSED to some package

The reason it *seems* to work is that printWorld and printGoodBye are defined in the same package.