I don't have biological children - I was never in a position where I would have considered it a good idea to have them (for various reasons, internal and external), and I've always seen it as about the biggest responsibility that you can have. However, about 9 years ago I met my current girlfriend, who had 4 kids from her 16-year marriage, and I'm now considered by them to be their step-parent.

I remember I found it absolutely exhausting when I first started seeing her - it took a couple of years for that to not be the case - and they are -not- difficult children; quite the opposite, they are all really wonderful, and we generally get on very, VERY well. But it's an immense amount of work, and every time my girlfriend compares herself to where she would have been had she not had children and committed her time to be (what I consider to be) and excellent parent, I have to remind her that she's been a full time + (and then some) parent for about 12 years. Returning to the workplace for her has been difficult as she now works a full time job as well as being a mum - and one who cooks just about every night of the week, and has generally impossibly high standards for herself as a parent; despite her/our eldest now currently studying at Cambridge University.

I can totally understand why some would regret having children; it's presented as being a utopian existence that you get immense satisfaction from in many quarters, and anyone who dares question whether it's the right move for them (or indeed their prospective children) is given short shrift. It's not for everyone, but everyone is expected to have children. I have been given long-winded lectures in the past for not having my own, and I'm sure anyone who dared to question the experience with said inquisitors would have a very hard time!