It has happened a few times to me. The alarm clock rings, I wake up to go next to it, then I wonder what I am supposed to do with it (what is it anyway)

Once, I switched it off, then sat on my bed. My head was completely empty for some time (maybe 1-2 minutes). Remembering which day of the week it was hadn't even a meaning, as the sequence monday-sunday had vanished from my mind too

Another time, I woke up, switched off the alarm clock, then went back to bed and fell asleep. To be precise, I don't exactly
remember that. I reconstructed it from fractional and vaporous remembers. In fact, I hadn't left my sleep state.
This led me to remember a very old experiment I had done, maybe 20 years ago. I had seen in a TV show someone having amnesia. I thought it was impossible, because I knew that when I experienced something it became a part of me.
So I did an experiment. A morning, when waiting for the bus, I watched a leaf whirled by the wind. I raised my level of attention very high, and imprinted every detail in my memory: where was the leaf, in which direction it went, the amplitude of the whirl, everything.
For years I remembered everything very well (mostly because I thought about it quite often). Then over the years it began to fade. Now I can remember the leaf whirling, but I am not exactly sure about the whirling direction: clockwise or counter-clockwise? Had it reached the left road? or the right one? I am sure I had imprinted those details too. Therefore, the experiment proved me that amnesia was possible, although it took easily 10 years

I also saw a very good movie about memory:
Memento. The scenario is quite common, and is in fact completely uninteresting. Only the non-linear way the scenario is depicted is the whole point.
The real sign that someone has become a fanatic is that he completely loses his sense of humor about some important facet of his life. When humor goes, it means he's lost his perspective.
Wedge Antilles
Star Wars - Exile