可能是用習慣了~
like, if u are the type of people who like to use the same password for every single website.. then changing the password to something else will be disastrous because sometimes you just forgot which websites you have registered. Sometimes we do browse websites that we seldom go to, right? If he changes the password to the ones he uses everyday but forgot to change the other ones... then he will screw up big time
it's ok ah, he loves YOU right now anyways.
Besides, if you want him to forget every girl in the past..
ask yourself, can u completely forget that guy in your past? Remembering someone doesn't mean you still have feelings for him/her. It is some memories in your life that you don't wanna forget. The memories are nice, that's all.
I know girls are very sensitive to guys' ex's.. for some reason, we girls always think that we can be very loyal and guys are often more flower-hearted

but he is special to you, so he's not like other guys = trust HIM!
Feel better soon oh~