I am the father of 21 year old fraternal twins, a boy and a girl.
You will survive the first 6 months on very little sleep, I got an average of 4 hours a night. When they SLEEP you SLEEP.
Post a feeding chart on the fridge and mark off who has been feed, so that you do not feed one twice and skip the other. BTDT
The first 3 years seemed like a 100 yard dash, before I new it the time had passed.
They will have a bond between each other that no one can step between. My daughter will be the first to say that she will kick her brothers ass, but you better not try.
As you can tell by my user name on BS, they are the most significant thing that has happened in my life other than marrying their mother.