People are looking for reasons and tendencies for the question why they like somebody. So if you wonder why two people like each other there are simply just 2 Options.
Option 1: You are the Opposite of the other Person
Option 2: You are the Same as the other Person
Both does not really matter, when you like each other but you will probably say: "Oh we fit together to well because we are so different, which makes it interesting".
On the other side you can also say: "We fit together so nicely because we have so much in common"
Both depends just on the relationship you have to the other Person and the rest you will figure whether you are the opposite or the same does not really matter anymore but you will always look for an explanation, why you are attracted to somebody.