There seems to always be lots to do!
Projects, hobbies -- reading, photography, learning a language, playing a musical instrument, exercise, cooking, gardening, time alone, time with friends, etc.
Sometimes when we have more time, we'll find it helpful, even necessary, to get to know ourselves -- What do we enjoy as hobbies? Where do our talents lie? What would we like to learn, or like to like to teach?
I have other adults (in the household) around 4-7 days a week. I never feel like I get enough alone time. That's just me though! We are all a bit different in our needs/interests.
WC