fake ratings??

so...I've struggled with this for a while. I'm a new-ish player, not that good yet. I fluctuate around 1050-1100. So, a lot of times I would destroy guys rated up to 200 points higher than me, but then also frequently get whipped by people rated significantly lower than me. I struggled to understand the frequency with which this happens. then today, they put me against this guy who's rating says 1200. he's literally playing the worst chess I've seen in a while and I dispose of him pretty quickly despite not playing a great game myself. whatever I think, maybe he's drunk, tired etc. he challenges me to a rematch. Now his rating says 983. What?? He dropped 217 points from one game? I don't think so. (the result of this game was similar.) what gives?

I think I found my own answer down a few threads. it was the guy's first game so he was 1200. that allowed the huge rating shift from game 1 to 2. makes sense now.