In my personal experience, I first heard of it 1 year ago in a online forum game, people sold gold for Bitcoins, around March, gave it no importance at first. Now im kinda utterly commited to it. Really an interest subject of study.
Me, somewhere from my mouth's friend, When he ask about job online, and he opened up about bitcoin, That's the start of my curiosity, All day long i read about news and articles about btc. and from that day i registered my self thru this site. I make used of my time in reading and posting ideas in discussion then it was so fun:)