Who knows?
I would guess at the final one - you picked up some early warning signs and started thinking about it.
The mind is a funny thing - on a rather unrelated note - I have an email address linked to an old isp dial up account. Because I don't dial up they suspend the account every 183 days and I have to log-in to the website to reinstate it.
I woke up one morning about 4.30 am, thought my email account has just gone off, went downstairs and tried it. Sure enough it was off. How on earth did my mind manage to keep track of 183 days to within a few hours without me knowing anything about it?
