can't create oracle user with name > 30 characters

[oracle@stormking cdb12102 ~]$ echo -n Supercalifragilisticexpialidocious | wc -c
34
[oracle@stormking cdb12102 ~]$ sqlplus /nolog

SQL*Plus: Release 12.1.0.2.0 Production on Tue Jun 28 23:17:06 2016

Copyright (c) 1982, 2014, Oracle.  All rights reserved.

SQL> conn u/u@stormking:1521/pdbm
Connected.
SQL> select char_length from dba_tab_columns where owner = 'SYS' and table_name = 'USER$' and column_name = 'NAME';

CHAR_LENGTH
-----------
        128

SQL> create user "Supercalifragilisticexpialidocious" identified by p;
create user "Supercalifragilisticexpialidocious" identified by p
            *
ERROR at line 1:
ORA-00972: identifier is too long