Furniture you assemble yourself feels more valuable than furniture you didn't

In experiments, people who built their own IKEA boxes, origami or Lego sets valued their creations as highly as experts' work — and far more than identical items assembled by someone else. Labour alone, even clumsy labour, seems to create attachment to what it produces.

— Michael Norton, Daniel Mochon & Dan Ariely, The IKEA Effect: When Labor Leads to Love — Journal of Consumer Psychology, 2012