Ok, not exactly a nightmare, but an idea, that comes to your not exactly right mind right after you start falling asleep. 

It's easy:

1. Try to fall asleep with 75% success, be very sleepy
2. Yet have a short riff keep circling in your mind
3. Don't be sure it's even an original one
4. Decide nonetheless to capture the idea, since no idea should go to waste
5. Without moving your sleeping mask, whip out your phone and open BandLab
6. Sing that melody beautifully
7. Play a proper piano accompaniment with three shaky fingers beautifully
8. Admire your coordination for a second and fall asleep immediately
9. Record that thing the next day
10. Congratulations, now it exists

I'm THAT close to start thinking about considering trying live looping, because I made this whole thing on AUM/Loopy and it wasn't painful at all. However, while eliminating dead air on (oh yes) GarageBand afterwards, the samples started to surprisingly and annoyingly fall apart timing-wise. I don't know what caused it, but I should consider eliminating GarageBand altogether.

So, today's sensation is that late-night tiny idea that I'm pretty sure was inspired by some cheesy Russian 90's song from my subconscious.

Anyways, extra enjoy that actual recording bit from BandLab in the beginning.