Having kids is the hardest thing anyone can ever do — I am thinking of counterpoints while writing, but none comes to mind. However, I recommend having children.
It is, contrary to some commenters, not a selfish thing to do, but a completely selfless act. You can see it for yourself when you watch the children around you: The pure joy of being alive! The full range of emotions! The good, the bad and the ugly…
You could argue that the children are thrown into the world and are now stuck with it, and you rather would prefer nonexistence to existence. If you can answer the question, is life worth living, positively, then you can argue, that existence is better than nonexistence and consequently being thrown into this world is better than to pass on the experience. It would, however, be selfish to keep this experience all to yourself and not allow potential offsprings to take part in this experience.
> You need to be very sure it's what you want. It will be expensive, it will limit what you can do in all sorts of ways, because it is relentless in a way which exposure to it as an aunt or uncle or friend simply won't communicate adequately
This is right! Having kids is total; It will dominate your life. Every second of your day for at least 4 to 5 years. If you are not willing or able to endure, then you should not have kids. And again: You cannot fathom what it means to have someone who is so dependent on you and the life and future depends on you. No, not even the clingy partner you had.
The hardship is soon forgotten — this is why the uncles and aunts and friends — don't communicate it adequately. These corny moments are real: Memories that will stick with you forever, even the bad parts, that somehow and with time get twisted into fond memories. (My son was crying every night for 8 months when he was falling asleep. I carried him on my arm until he was so exhausted that he slept. I sang songs for him for hours. Then he would sleep from 11 pm to 4 am. So at 4 I went to the living room with him, and we tried to catch some sleep on the couch. It got better after thees 8 months, but what a ride — now I like to think back and miss these nights when he slept in my arm).
You might be in these first years, or I am having a short respite, but it gets easier after the first years. But you don't have kids for yourself, but for your kids.