The question is:
When am I not in TeX.SX?
Usually as soon as I have access to the Internet, I connect to this site more like how people do with facebook. What is your case?
I think I'm not on TeX.sx when... well... I have no idea. :)
After all, last time I wasn't here was April 23, 2011, according to my profile. :)
When
Microsoft releases a better typesetting system than (La)TeX. It is not necessarily free of charge.
...
All copies of (La)TeX distributions on the earth are destroyed by Aliens.
To be honest, I'm usually only on when I'm thinking about LaTeX. So if I'm writing or editing something I'll often log in. However, if I'm trapped in MS world land or not writing anything, then I'll forget to log in.