When I first picked up his books while at school I was already interested in history, but my areas of interest had been rather tightly restricted to what we were being taught in school. Which didn't extend to much beyond the First and Second World Wars.
Up to that point I had never independently gone out to study other periods of history. But as I was reading about the exploits of Garion, Belgareth and Sparhawk - with all of the knights, battles, sieges and medieval imagery that surrounded those adventures I distinctly remember my interest being piqued.
For the first time I went off and decided to learn more about the real inspiration behind these characters - going out to buy a number of books on medieval knights and the crusades. From then on I would leap from historical period to historical period as my interests fluctuated, researching as I went and learning about new, different periods of history. Reading Sharpe? Off to the library to read about the Napoleonic Wars. Just watched Gladiator? Let's read about Rome!
I was lucky enough to have the chance to speak to David Eddings while I was fresh out of university and working as an intern for his UK publishers - I think I managed to not come across as too much of a geeky fanboy, but a small "I loved your books as a kid" did slip out! I still have the full set of the Belgariad, Mallorean, Elenium and Tamuli stashed somewhere. I might just pull them out sometime soon and re-read them for old times sake.
Perhaps it was fate that Eddings had such a large impact on my life - after all, the order of knights which feature in some of his books are called Pandions.
And Pandion is Latin for... Osprey.