Children are chaotic. So are relationships with other people in general. Mostly, though, you can tell another adult what you need or do not need and generally get an appropriate response.
For myself, I've found chaos is important. If left to my own devices, I trend towards a general peaceful quiet hum interrupted by occasional bursts of a desire for wildly new things. I've found living with other people, and being in a relationship with other people, is like a dice-roll that allows for an injection of chaos. Sometimes good, sometimes bad, but with enough volatility that my mind is kept busy.
For myself, as well, I need to balance this with alone time. Time to actually let myself spread thin into my own experience without external input. Well, without external 'conscious' input. Environmental input is fine. To be alone with my thoughts.
In a relationship, I've generally been able to do this, though given my general attraction to more outgoing gregarious people, it usually takes a bit of a lead-up of explanation that it's not them, it's me. That my desire for alone time is not a reflection of my desire to not be with them. It's a desire to be alone with myself. A necessity for me to be a good citizen both in a relationship and within society.
Children are a whole other ball of wax, though. A whole different kind of chaos. Untamed chaos that do not understand the necessity of alone time. And sometimes the chaos they can inject in a situation is very detrimental to the nerves.
It gets better as they age, and as they begin to understand. I also feel like I'm probably describing nearly everyone's need. To be sometimes alone with themselves and their thoughts. It's hard to say, my own experience is my only experience.
The thing with children is, for all the negative chaos they can create, they create so much good chaos as well, and the chaos begins to form into order based on your interaction with it. It's amazing to see.
I guess what I'm saying is, I've come to believe in chaos as an important part of my own happiness and traversal through this life. I tend towards a kind of order that leans on routine and because of that I do things to inject change where I can, and a great way is other people. And children.