Sleep

You decide that your first course of action in a world without any people is to go back to sleep. I mean, you DID stay up pretty late last night, and you only got up because you had obligations for today, but if there’s no one else around to make you do anything, why not get that extra sleep you need? So, you close your windows, draw the blinds, turn off the lights, and lay back down in bed. After a solid 15 minutes of trying to force your body to go against your circadian rhythm, you eventually manage to drift peacefully back to sleep.