I work with young children, so have a much clearer idea of what it’s like than I did, say, 5 years ago.
Yeah, I thought that too. Sorry OP, I've worked with kids my whole adult life and love it so I believed I was prepared for the realities of having a child of my own but I was wrong. It turns out nothing can prepare you for parenthood.
The love you feel for your children is overwhelming, like nothing you've ever experienced and there are certainly moments of pure joy. But with that comes an immense weight of responsibility. There's a lot of worry, constant guilt (the nagging voice in the back of your head wondering 'am I doing enough?'), exhaustion and the biggest change, for me anyway, the loss of freedom. The baby toddler years are utterly relentless, they're so dependent on you that their needs are all consuming and your own needs and wants don't just have to take a back seat, they get lost entirely for a while. I'm not talking about the freedom to go for long boozy lunches or spontaneous weekends away (although obviously those are out too!), but little things you've always taken completely for granted like the freedom to eat when you want and to wash your hair when you want, not just when you 'get the chance'. And I certainly wouldn't have DC in the hope it will make life "more exciting" or you're setting yourself up for disappointment. So much of it is drudgery and endless repetition in the early years.
I remember when I was pregnant with my first people kept telling me "your whole life is about to change" and I thought "yeah, I know. Obviously
" but I honestly don't think I appreciated that everything would change, and that it would change so completely. Then, all of a sudden they get to about three years old and you realise that you can leave the house without carting loads of stuff about like a pack-horse. Eating out becomes a treat again rather than an exercise in public humiliation. You can actually leave the room for a few minutes without worrying they're going to do something completely bizarre and reckless that might get them killed. You start to get your life back, basically. Then if you're anything like me you get all hormonal and broody, forget how hellish the baby/toddler stage was and have another one 
Honestly though, I wouldn't be without them. Yes, I sometimes fantasise about faking my own death and starting a new life somewhere nobody knows me, but just when I think I've reached breaking point one of them will do something so fucking adorable that it melts my heart.