Why my HEADING_TITLE do not display on Pages?

for example,

I check the includes/languanges/english/create_account.php, there is a line :

define('HEADING_TITLE', 'My Account Information');

and the i check includes/templates/template_default/templates/tpl_create_account_default.php, there is:

now i open the browser and preview the site, in create an account link, i view the html code, it show:

where goes the HEADING_TITLE? which shall be 'My Account Information'

Are you logged in?

not yet...

but should have the title whether login or not

i mean, all HEADING_TITLE do not show, inlcudes:

conditions
privacy
shopping cart...

My account is a conditional if/else...
The others are not
How can I assist if you do not provide a link to your install?