My account got compromised =(

Something which I thought would never happen to me has happened to me for the 2nd time! My Googs got compromised! First it was my yahoo account. This was a couple of years back I was using it nicely and suddenly to my utter surprise, I could not log in. Someone had gotten in and changed my password. Why do people do these things? Anyway, really sleepy now. Going to Zzzzzz