The 3 PM Shutdown

I think I’ve reached the age where I have to take a nap in the afternoon. Or something else.

It started a few days ago as a “sleep attack” around 3 PM. My eyelids get heavy and close. The moment I lie down, I doze off into the twilight phase before falling asleep (hypnagogia). I wake up two hours later, thinking it’s morning. I force myself to go for a walk, which wakes me up.

It’s not a painful experience, just curiouser and curiouser. Is this a side effect of chemotherapy on a background of morphine-induced drowsiness, or am I turning into a narcoleptic day vampire?