"Despite the saying about opposites attracting, people usually fall in love with people like themselves. There's even some evidence that people tend to pick partners with noses of similar breadth to their own and eyes about the same distance apart. At lunch, Harold and Erica quickly discovered that they had a lot in common. They both affected connoisseurship regarding prosaic things such as muffins, hamburgers, and iced tea. They both exaggerated their popularity in high school, and had the same opinions about the characters in 'Mad Men.'
People generally overestimate how distinct their own lives are, so the commonalities seemed to them a series of miracles. The coincidences gave their relationship an aura of destiny."
-The New Yorker: Social Animal-