Ohh this is so shameful but here goes...
Back when I first heard about Avril, like 2002 or whenever, I actually hated her. I only really started liking her summer of 2007, even though when I first saw the video for Girlfriend I hated the song! But I thought Avril was pretty hot - this was when I was first intereterested in avril. Then when I heard/saw When You're Gone I like fell in love with the song, and video
But it wasn't until september until the 'addiction' really started; I remember it so clearly!... It was the week of Avril's birthday, and MTV Flux were showing Avril's video's ALL DAY for like days... and it was the only decent thing on TV so I just watched it for hours. I'd never really listened to Avril before or watched many of her videos; This was the day I fell in love with Avril
haha.
Also, on a more personal level, Avril's music helped cheer me up - before then I was listening to shit like My Chemical Romance, who I now detest(even Slipknot's better than them!! who im listening to now. haha).
I almost lost a friend in an arguement about why I liked Avril... she thought I was just shallow and thought it was only because I thought Avril's hot [which she is]. But Avril and her music means alot to me. 
Can you believe it! 5 years ago I couldn't stand Avril. Hated her. Thought she was some lame American.
LOL
[Yes I know Avril is canadian... lol]
and now 5 years on I own all her albums and have tickets to one of her gigs!
Amazing.
Although unfortunately
almost everyone I know hates Avril
and guys at college take the piss outta me for liking her! It kinda sucks. But hey, they're the losers not me
So yeahhh. That's when my "addiction" started etc etc.