This applies to only lexical variables, by the way. Dynamic variables continue to work as they have always worked. Closure is not something that most Perl programmers need trouble themselves about to begin with. References are often returned by special subroutines called constructors. Perl objects are just references to a special kind of object that happens to know which package it's associated with.
Constructors are just special subroutines that know how to create that association.
They do so by starting with an ordinary reference, and it remains an ordinary reference even while it's also being an object. Because we haven't talked about dereferencing yet, we can't show you any examples yet. This might change in a future release. That's it for creating references. By now you're probably dying to know how to use references to get back to your long-lost data.