1. Your kids will keep asking why you got divorced.
Decide what you want to say to your kids and stick to it. They will ask at unexpected times in new and interesting ways. They'll ask one night when they don't know that you're really pissed at your ex. This is not the time to vent and spill all. Keep it simple and keep yourself together. Know what your stance and stay the course.
2. People say stupid stuff.
Until you go through something, you just don't know. People tell me all the time how lucky I am not to need a Saturday night babysitter (when my kids are with my ex). I got divorced, my life and family broke apart, but I'm so lucky because I don't have to deal with finding a sitter. Really? People don't mean to be insensitive, they just don't know because they haven't lived it. Give them a break; especially in this case because it is a nice perk of a sucky situation.
3. You will be put in the position of defending your ex's girlfriend.
It will happen. It doesn't matter how fun she is, they will get annoyed or mad and tell you all about it. Put your game face on and defend her. Show solidarity with the other adults taking care of your children (then go call your girlfriend and gloat.)
4. There is no privacy.
The sign of a "good divorce" is that kids feel comfortable sharing freely with both parents. You have lost your right to privacy so beware, you ex will know about everything that happens in your home.
5. Your kids will ask your new boyfriend whatever they want.
Friends and family know better than to ask your new boyfriend if you will get married and have a baby. Your kids however hold no such boundaries and have no reservations when confronting the new interloper. I hope your new man has a sense of humor like mine.
You're stuck with your ex.
If you have kids together, you are stuck together indefinitely. Moving past the ugly sh** that went down in your marriage can be near impossible at times. If it is, get help. I now go to counseling with my ex. I often imagine a colonoscopy twice a month would be more enjoyable than our therapy sessions. But they're helping. Do what you've gotta do. You may have divorced, but you're still stuck with him.