Blizzard defines genres the same way a dictionary does; it gets you the basic concept and leaves you with a general working knowledge, but you'll never full understand the full depth of the word unless you look to other sources.
Actually it was Star Wars: Dark Forces II: Jedi Knight for me. I was a SW fanboy at the time, had a clan and everything... back when you could play real video games through MSN's Gaming Zone. I got into StarCraft later than some. ;-)