So, when I'm really exhausted (for example, today) I sleep a lot (for example, the last hour). And one of the things that happens to me a lot when I sleep irregularly is that I'll wake up a little bit, think of something that I need to do, and then, instead of actually doing it, I'll dream that I'm doing it.
I just woke up enough to actually write this blog post, but it followed this sequence of events in my dreams:
I was (actually) woken up by my phone buzzing. I dreamt that I picked it up, saw emails I needed to respond to, and started responding. At that point, I realized I was dreaming, and was going to need to do this in real life. So, I dreamt that I reached into a drawer that isn't actually in front of me, and started writing a note on post-it notes that aren't actually in that drawer.
Then, it occurred to me that that would make a good topic for a blog post, so I dreamt that I started a note about that, when I realized that I could tell my arms weren't actually moving, because obv, because I was still asleep. So I tried to reach forward and actually open the drawer (which was still very much not in front of me) but couldn't make myself reach. So I decided to just hope that thinking this much about it would make me remember to actually write this post. (That never, ever works, but I decided to write it right away when I woke up.)
After that, I got back to responding to emails. (In my dream.) One of them was to my boss, and I composed it, and I hit send.
That was when I realized that (in my dream, for some reason) there were a bunch of embarrassing links to websites in my email signature that I wouldn't want to send to my boss. I panicked, and that woke me up, which is why I had the energy to start actually writing this now.
The problem this habit most often causes for me is that I will dismiss my alarm in the morning, then dream that I'm setting a new one for later. I've also definitely thought that I'd done things because I'd dreamt doing them, and I've thought people were trying to get in touch with me because I received a text and dreamt that it was from the wrong person.