Then I took a train to another city, but I woke up next day in my bed. I don't remember anything from last night, only today I noticed the flex ticket I bought at the train station from my town Neustadt to Regensburg....
What was I doing in Regensburg? How did I get home? How can I do this "difficult" things like this during Blackout?
I have some flashbacks, I was sitting on a train, the conductor asked me for a ticket. That's all. I don't remember any more.
How did my brain get me home? How does it work?
I am sure something fun was probably going on in Regensburg ;)
Edit:// to go into more detail. I've seen and had this happen (f* alcohol). It surely decreased by drinking enough water and some club mate between beers :) Obviously anyone can tell you are drunk, but it doesn't mean you don't function. Also due to alcohol in general bad ideas turn into the best ideas ever and trips like yours can happen. Others awake next to people they don't know, or in a hospital. Count yourself lucky and learn to drink more water when drinking ;)
And it’s not super well understood. Aspects of dissociation are probably involved - if such a thing happened without the presence of alcohol or with a relatively low amount it might indicate a dissociative disorder.
Basically, you are able to function. That is, make decisions and take actions. The reasoning sometimes being very strange. But making "sense" in that altered state.
But, the brain is not storing any memories or only brief flashbacks. So the executive parts of the brain kept functioning, i.e. you did not lose consciousness.
Brain studies demonstrate that different parts of the brain are involved in different functions. It is well known that alcohol can lead some people to lose inhibitions. Some people become more aggressive, others just want to sleep. So in the situation you describe as blackout, memories were not formed.
The last thing I remembered was we standing outside of the venue, giving away MDMA to our new friends. That was at 3:00am.
I was trying to talk, but could not get my mouth to work. Super strange!!! I felt powerless and went trough my pockets, where I found a flyer of a hostel. Luckily it was the hostel me and my friends were staying. Taxi driver was very polite and probably a little worried.
Slept till 20:00 like a baby. Woke up 100% normal again.
You may have "passed out" -- which is a loss of consciousness.
At some point you recovered from being passed out (if you were-- we can't trust your memory), but you still had enough alcohol in your body to be "blacked out" which is the inability to form memories.
People can be surprisingly lucid during a blackout.
You also could have gone home mostly sober and drank enough you can't remember the evening.
Doesn't hurt to see a doctor.
DuckDuckGo result includes a video: https://www.youtube.com/watch?v=zdofbRjXHkQ&t=29s