When Alexia Metz thinks back on the early years of parenting, she mostly remembers the stuff. "I was living in a small condo and had twins," she said. "I felt like the walls were closing in on me."Subscribe to The Post Most newsletter for the most important and interesting stories from The Washington Post. Many parents of young kids may feel pressure to fill their homes with toys, especially this time of year. But after researching the topic with her team at the University of Toledo, Metz, an oc