I'm 19 years old and from Flintshire in North Wales. At Sixth Form I studied 3 A-Levels - Maths, Physics and Law (AAA) - and an AS level in English Literature (B).
After leaving school I took a year out, where I spent 6 months teaching English in Sichuan Province, China. I have a blog of my experiences there.
After returning home I worked in a number of jobs. I also attempted a walk from my home in Wales to London to raise money for the victims of the Sichuan Earthquake. (Website here). Although I didn't complete the walk in one go as I had hoped, I did manage to finish it over several weekends, and raised over £2,700.
Why did I choose CS? I guess it's because it's such an exciting field, that is causing such a big impact on the world, and is likely to become even more important in the future. Also, I find some of the theoretical side of things quite interesting, though I'm glad thats there's a strong practical element as well (that's why I chose it over Maths).
I had some limited experience of programming before I came to university; mostly QBasic and VisualBasic. Probably the most complicated thing I had programmed was a hotel booking system in VB, which was for my AS level ICT coursework (however I dropped that subject, as ICT doesn't really involve the more in-depth aspects of computing that I wanted to study.)
I didn't really have much experience of the other areas of the course, e.g I'd hardly ever used Linux before I came to Warwick, only knew some basic HTML and no CSS/PHP.