This question came in reponse to one of my many rants about my research, and was also asked at my Viva for my first year report. Well, having graduated with a degree in Environmental Chemistry from Oxford Brookes University in 1998, and then spent 3 years as a chemistry technician in a school, I felt I needed some new intellectual stimulation. So I went looking for a PhD project... during my search I saw an ad for an open day for the Chemical Enginieering school at the University of Birmingham. Now I didn't even know what Chemical Engineering was, but I thought I would go along and find out, especially since I could visit Gardener's World Live after I was finished.
At the open day there were about 6 projects I was interested in... but I think they were more interested in me... I was almost pounced upon.... and I think the choice of project was made by availability rather than the logical process, that I usually use... it was almost as if the project chose me. Maybe that's why I get so angry when things go wrong... but here I am doing what will be very interesting research, into a subject which is very relevent to my first degree, although it is extending my skills far beyond anything I would have expected.
Basically, what got me into this was my insatiable curiousity, and my ability to be interested in almost anything.