That is a normal reaction. You haven't seen him for 12 years but you have stayed in contact and know what each other is doing. It's not all catch up but as your brother both of you would have changed and aged but nothing has changed as such. You have both grown but the base is still there. I hadn't seen my brother for ages and was a little shocked as I hadn't seen photos so had the last picture in my head. It is amazing how the body changes but the person doesn't really.