Definitely not the same. I feel when you dream you feel some time has passed. I've lost consciousness a number of times for different reasons and the common feeling is it doesn't feel like any time has passed. One moment I was awake and the very next I'm on the ground, my head hurts and have no idea what is going on.. for the first 30 seconds I wouldn't be able to tell you my name, where I am, what I was doing, etc. Then it all just comes back after a minute or two and you realize what happened.