Starts, like most things, from childhood. I had a lot of the original Lego Space sets, although as the years progressed they made way for the new kid on the block - home computing. So all the Lego went to charity and a brand new Atari XL filled the gap.
I hadn't looked at Lego for many years, then in 2002 I saw the Lego Adventures series (specifically desert) on eBay and as I am quite a fan of ancient Egypt, thought it would be a nice fun addition. From there I got the Lunar Lander (Discovery Ed) as I am a fan of spaceflight, then it was the entire Indy collection & the Death Star.
Since then I have added the Shuttle, the Camper Van and the festive sets to what seems like an ever growing collection.