They’re old enough that you don’t feel stupid when they beat you at videogames. Much.
No babysitters necessary. In fact, they *are* babysitters. Ha!
You can talk to them. About grown up stuff.
They can pull their own weight. Chores, jobs. Driving! (OK. This one is debatable.)
They still do silly stuff that you can laugh about later. Like nag you to buy a bucket of chicken from KFC so they can pretend they’re Buckethead.
You can actually enjoy going shopping with them! And make them do all the work.
Your mommy radar doesn’t go off every half hour. You can let them go swimming without worrying about them drowning every three minutes. (My personal paranoia.)
No more sitting through Pokemon: The Movie. (Hallelujah!)
You can watch scary movies with them and laugh at each other later for hiding behind your sweater.
When they’re not getting along, one of them will write something like this on the bulletin board.
They say funny things, like “Stu-P. Diddy.” Or instead of “I see dead people,” it’s “I see tomatoes. Just around, like regular tomatoes. They don’t know that they’re tomatoes. But they are.”
When they’re quiet for awhile, it doesn’t mean you’ll find the kitchen cupboards coated in peanut butter and flour. It means they’re all actually getting along.
…I won’t go into the disadvantages.