'My boyfriend knows more about me'

Dear Mandodari,
Of course you should find out information about his background. The next time he asks you a question, casually ask him the same about him. Being on social media, there is no personal interaction so things need not be exactly what meets the eye. Gradually ask him about his likes, dislikes and his family members. If he evades replies, things are amiss, then you should be wary and cautious. In a relationship both should respect each other. In your case your guy appears to have an upperhand.