Correct. Perl maintains a global %INC hash, listing all modules that have been required (use is just a special case of require). If a reference to the file already exists in %INC, it will not be loaded a second time.

If you wanted to force Perl to reload the module, you could delete the reference to it in %INC (the key is the file name, which can be absolute, or relative to one of the directories in @INC). There aren't many cases where you'd want to do this, of course. (One legitimate case is Apache::Reload).