How much sleep do you need to wake up happy the next day?

Lots. 8-12 hours is best to get true beauty sleep and avoid dark circles under the eyes.

Just enough. 5-8 hours is enough to feel rested, because anymore or any less would result in feeling drowsy.

A little. Less than 5 hours. Sometimes there isn’t enough hours in the day to get things done.

Depends on the mood or day.