When you have a large space, it's tempting to fill it with stuff. However, the more belongings you own, the more your belongings own you. Humans are the only living things that build emotional relationships with stuff (ever seen a monkey petting a rock?), and if our possessions break or fall into disarray, we start to worry about them. The less stuff you have, the more emotional bandwidth you reserve for the things that can love you back, like loved ones.
The tiny transition: I suggest conducting a simple "time-use survey" of your own home to figure out which rooms you actually use on a regular basis. Using a calendar or journal, estimate how many waking hours you spend in the various spaces inside and outside of your house each day, noticing the most-used room after a few days. (For most Americans, it's the kitchen.) The process will illuminate the most effective floorplan for your next move or remodel.