I'm pretty close with a lot of my colleagues who are between 25-33 (I'm 37). I find the younger ones very difficult to relate to, so when they have children I think I will struggle. In my main friendship group, I'm the only childfree one and I find it very frustrating, you're not mean, you are being honest - it's one of the reasons I don't want them. One of my friends said to me 'its hard work having two children' - well yeh, I could have told you that!
ETA; sorry that's written so badly, I clearly need to go to bed!