Anyone experienced sitting then suddenly the alarm sounds as if no time had passed and you have no recollection of what just happened in your sit? As if I took a nap, but I swear my eyes were open. I remember feeling really sleepy though, and feeling very refreshed after sitting. This also happened once or twice during the rohatsu retreat.
I'm primarily concerned if the Soto tradition has any warnings against dead sitting or similar stuff, as this seated nap thing could be it? What's dead sitting anyway (not asked in a koan sense)?