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.
If I remember correctly, I heard the word bitcoin when I was in college but I ignored it because I'm in the middle of a thesis at that time then last month, my friend introduced it to me again and began to have interest in it and I see the bright future ahead of bitcoin so I decided to jump in and try to earn bitcoin for my future too.