When Did I Start Wanting Collectibles?

It's kind of safe to say I'm obsessed with Harley Quinn. Everything from her personality, costume, back story, and bad love choices really interests me. This past month I went to C2E2 and bought 2 new figures of her, one being limited edition and numbered.

Black and Red seems to be a reoccurring theme. 

So for the moment I have 3 Harley Quinn figures, but I really want more. Like, a huge glass case full of them. I want to get lots of art also commissioned to have original drawings of her. I'm even considering the comic collecting, which seems a tad tedious to me, but it would round out my collection. 

Another thing to consider purchasing is the Injustice: Gods Among Us video game, considering she does have a good chunk of relevance in it. As well as going back and buying the Arkham video game collection (Asylum and City) since she is in those two.

I also am very excited because I want to get a Harley Quinn tattoo with James getting The Joker one to match. I definitely want it as my 2rd wedding anniversary gift.

Is there a comic book character, or any personality (TV, Books, Movies) that you are pretty caught up in? Do you have collectibles? Would you get a tattoo of them?