Obviously we want to have a child because of the joy it brings and stuf, but there are reasons you might think of that you probably wouldn't actually want to tell a social worker
1: I want a child so I can justify getting a dog
2: I'm doing it so I get shit loads of karma Nectar points. After this I'm sure to come back as something really cool like a dolphin and be a good half way along the route to Nirvana (if you're into that stuff)
3: Someone's got to look after me when I'm old and decrepit
4: An adoptive child might be more attractive than my own and may get sort of lucrative child modelling contract. It sounds cruel, but with some of the thinking of our current government and some of the ideas floating around the Republican candidates in the US, any of whom who could be leader of the "free" world, it's got to be better than making them clean chimneys.
5: Lurking round Toys R Us, playing with toys I want and not looking like a paedophile*
6: I can't be arsed to demolish the child's play house we have in our garden
7: It's going to force me to curb my potty mouth around the house
8: I eventually get someone to do chores round the house. After a few short years I need never pick up a lawnmower again
9: Hot chocolate at bedtime, seeing 3D Pixar films, getting all sorts of stupid kids cable channels, cartoons and sweets. Lots and lots of sweets. Real sweets like sherbet lemons, Kola Kubes, and Matlow's finest like Swizzles, Refreshers and Drumsticks. Not sure what the kid's going to have, mind
10: Christmas, Hallowe'en, Bonfire Night, Easter, birthdays. Actually, sod it, since one of the things we have to be is how sensitive to multiculturalism we are as a family, we'll also celebrate Eid, Divali, Hannukah, Chinese New Year, St George's, Patrick's, David's and Andrew's Days American Independence Day, Singapore National Day and May Day. Basically, any excuse to eat shit loads, give presents and have a good time.
*The "P" word is definitely one that I think will set off alarm bells in social worker's heads, whatever the context