Don't understand

How is it that a person can feel ok one minute and then be completely depressed the next without anything triggering it? Just can't comprehend that. I was feeling ok earlier. Managed to get in the shower and was going to run an errand. As soon as I got in my car my whole mood changed. I felt the darkness wash over and consume me in a matter of seconds. Almost as if some unseen being knew that my errand was not going to go as planned and brought the darkness upon me to ensure that I'd behave in typical borderline fashion. It defies logic and therefore isn't sitting with me well.

I was going to renew my license plate since it expires today. Drove over to the DMV, but found out they were closed on Mondays. Wasn't too upset by that, just thought to myself that I should have checked first. So then I drove around to find a currency exchange to buy it at, which didn't take too long to find one. They however told me that the DMV computer is down and they can't give out stickers without getting confirmation from the DMV first. At this point I raged because I tried to do something I was supposed to and as usual, I ended up fucked. I'll head out to the DMV tomorrow, just hope I don't get a ticket for expired plates on the way.

Could I have subconsciously known I wouldn't be able to get the sticker? Is that why my mood changed as soon as I got in the car? I couldn't possibly have known though. I remember thinking earlier that the DMV might be closed on Monday, but didn't make the connection between that and today actually being Monday. That's why I wasn't too upset when I got there and they were closed. But there's no way I could have known their computer system was down and I wouldn't be able to get a sticker from the currency exchange.

Is the mood change simply a coincidence? Logic tells me it has to be because I don't believe in ESP and all that fortune telling crap. But nothing else triggered the mood shift, it was almost instantaneous. Weird...