Everyone times out after being inactive for a certain length of time. Having the “Remember Me” checked just eliminates the nuisence of having to go through logon process everytime you return to the forum. If you were in the middle of working on a post and leave your session idle, you could time out and whatever you were working on could be lost as a result.
I’ll be the first to confess that there no special privileges for Site Team members and I can’t count the munber of times I’ve lost my work because I left my session idle for whatever reason and it timed out.
The best advice I can provide at this time is to do what I do. If I even suspect that my session has been idle for a long period of time and I might have timed out, before you do anything else, position your cursor in the text of your message, do a Select All and Copy all your text. Then open another JOF session in a new window or tab and open a new thread or post and paste the text you copied into the Message area. when you are satisfied that you have everything from your old session, end that old session.