Careful, this statement is misleading:

> The leaks that come from forgetting to free something go away entirely.

Not quite: In manually-managed and referenced counted languages with destructors, releasing resources, (open file handle, open socket, open connection to a database, ect,) happens when objects are cleaned up.

In a (tracing) garbage collected language, releasing resources is a very manual process. You might not have a memory leak, but leaking file handles or similar resources is a real problem with real consequence.