Scratch that, I just had to flush the cache it seems. I'll keep testing.

I downloaded version 7.2 but it still shows the real first name on the top right hand side.

I signed up, you seem to have confirmed.
I subscribed but I cannot download.

Subscribing is required to download component files

Thanks very much Michael.

I will provide an updated DisplayUsername component
on https://comz.z-mans.net/group/178/about
later today fixing your issue.

So, there's no need to apply any changes to the White theme.

You need to edit the theme sidebar

My question is not why I need to do it but how :).
I assume I can use the helloworld or customstrings component to change this behavior?

Because it will freak users out that think that only their username is supposed to show.
Can it be changed to the username?

Ok if user see his real name on top right corner what is the issue? because only account owners can see not others.

I had not but if I do that, then I see the real first and last name of the user in the side menu and the real first name next to the house icon.