I know exactly what you are talking about. Earlier in the year I became hypomanic, bordering on manic for 3 weeks. Everything I was doing/experiencing was the same as when I had been hypomanic in the past. I had tonnes of ideas, everything was awesome, was out running till midnight every night, getting heaps done, drinking more, no need to eat or bathe, and I was starting to become delusional.

I saw my psychiatrist who could see that my mood was high, but when she asked about sleep I said that I was having trouble convincing myself to go to bed, but once I was there I was sleeping 8hours. She said that it didn't make any sense, but everyone around me could tell that I was unwell. She increased my meds and after a few days I had gone back to 'normal'.

I have thought before that since I have been on medication (a few years) I'm not sure that sleeping is as good an indication of my mood as some other markers. For me one of the first things I notice is that I have no need to eat at all. Like there's no time, or I have enough energy without needing to eat. I sleep better on my meds than I ever have in my life, and I think that stretches into a mood episode too.

When I was in hospital a few years ago it was the same thing. Sleeping all night and hospital-grade mania all day.