So I was putting a new cog on yesterday and a neighbour came by for a few minutes to talk. I didn't have anywhere handy to put the old one so I just screwed it onto the freewheel-less freewheel side of my hub. I tightened everything up and put the wheel back on.
I hop on to see if 45x16 is really that much different than 45x14. I got up to a good speed and tried to skid. I felt the cog slip more than a little bit and figured that it just wasn't tight enough in the first place. No big deal. I'll just ride home and really crank the sucker down. I applied backpressure but instead of slowing down, I got NO resistance. I stopped pedalling and thought two things: Great, I just stripped my new hub; secondly, how am I supposed to stop this thing? Luckily, I live on a street with only occasional traffic so I had time to carefully stick my shoe onto the back tire.
When I finally got off 100m later, I looked at my hub I realised that I hadn't stripped my hub but rather I chained up the freewheel side by accident and it had unthreaded itself when I tried to skid. As I walked the block back to my house, my neighbour just laughed at me and promised to tell everyone she new.
The moral of the story is to watch what you are doing and not to ride barefoot.