I had been taking DayQuil, which does not make one drowsy. And I had also been taken Advil Multi-Symptom cold medicine.
Since I lost the box a few months ago, I had just assumed that it was non-drowsy like DayQuil. But then I went to the website and found that it is not. It has stuff in it to make one drowsy. I am not complaining. At least it explains why I have been awake and alert one moment, and slumped over the side of my couch the next.
I wish I known earlier though. Markus and his friend were going to come over for dinner, but I just become so devastatingly tired that I couldn't eat dinner myself. Instead I took a glass of water and went to bed.