If I could get even higher, while spending less money, why wouldn't I? Between those factors and my completely non-chalant, I-don't-give-a-fuck attitude, I was bound for addiction. At the time I honestly didn't care. I was more concerned with isolating myself and putting powder up my nose.
Plus, before you are physically addicted, words like "addiction, "withdrawal", and "soul-less" just don't have the same meaning until you go through withdrawal and addiction problems. You could know what to expect and have read about WD symptoms and personal stories, but when you're a naive youngster living in a heroin bliss, those things just don't really mean anything...yet.
Additionally: If you're a person who loves drugs (like myself), loves trying new things/new experiences (like myself), and has a curious nature (like myself), going from only knowing about it from DARE, to seeing it in scenes in movies, to reading very different stories on erowid, to reading it's king of the opiates on BL, well needless to say it made me extremely curious about trying it.

Now it's this way with meth for me, but I've never even seen it...
Anyone who likes oxy, or any other opiate, and doesn't have some prejudice against heroin, would almost definitely enjoy heroin.