So does that mean Create table statements force a commit to the DB even if Autocommit is 0 and I never explicitly called commit?

Try it and see. I suppose it makes sense; CREATE TABLE is DDL; INSERT is DML; and only some databases (PostgreSQL, for instance) know how to do transactional DDL.

Transactional DDL example:

# begin;  --> start a transaction 
create table testtable(id serial, c text);  -->  ... and create a tabl
+e
BEGIN
CREATE TABLE
# insert into testtable (c) values ('this will be short-lived');  --> 
+insert a row
INSERT 0 1
# select * from  testtable;   --> have a look
 id |            c
----+--------------------------
  1 | this will be short-lived
(1 row)

# rollback;  --> go back to initial state before begin
ROLLBACK
# select * from testtable;   --> now the table is gone...
ERROR:  relation "testtable" does not exist
LINE 1: select * from testtable;
                      ^
[download]

You get the idea...

Update: added a DDL transaction begin-create-rollback session.