Is it possible that a bad relationship can make you stupider?

Is it possible that a bad relationship can make you stupider?
The past few months I've noticed that my mental abilities have made unusual leaps forward, especially in light of the general decline they were mired in before. I'm a pretty intelligent guy and I have an unusually good memory, but recently I've been operating at a level I haven't known in years.

In high school and in college I participated on trivia teams, traveling the country flaunting my useless knowledge and getting drunk. Many nights of NTN trivia in bars back in college pretty much went the same way. After college things started to get a bit rusty, both in terms of memory and intelligence, but nothing major. One way or another, it seemed to get worse in recent years, corresponding with my last unsuccessful relationship. I couldn't speak German (not even to two cute young drunk German Au Pairs), I couldn't solve puzzles like I used to, and I didn't even pass a Jeopardy pre-screening (previously I scored a very nice passing score on the official test, though I wasn't selected to be on TV). I kinda gave up on some of what I used to be capable of. Don't get me wrong, I wasn't senile or anything, just closer to average.

Well, in recent months I've had a renaissance. I'm now magically able to speak and write German as well as I could in years. I watched Jeopardy a couple times recently with a friend, and I can answer all but a couple questions, usually real quick. What's odd is the stuff I'm remembering is not even the usual shit, its like stuff I'm pulling out of my ass. Brownian motion, Bernoulli effect, WTF? It's not just this relatively useless stuff either. I'm remembering all sorts of old memories, people, places, feelings, etc I'm working at a high level, thinking pretty well (well I still can go overboard and overdo things), and I'm able to read and learn at my old rate.

I can't think of anything else that's changed in my life, and I cannot figure out why things would have changed. I'm not trying to blame anyone or anything, rather just noticing things. I suppose some of the positive developments in my life may have brought this out--if so, thanks friends, you guys (more often than not gals) have really brightened my life. Anyway, it's good to be my old self.