The Boston Globe article is only a comment. Read the original source instead:

http://www.psych.ubc.ca/~edunn/publications/dunn_aknin_norto...

Things can make you happy if they hold sentimental value. That Timex or Rolex could hold significantly higher value if it was a gift from someone you hold dear. Of course you could argue that it's the same thing since it has a memory bonded with it.