Is it normal to collect porn so much?

I collect a lot of things - postcards, DVDs, stamps, coins. But I do not collect any of these things like pornography.

I might not even be feeling horny, but late at night I will literally sit for hours opening tabs and tabs of free porn videos to save, and downloading hundreds of pornographic pictures. Even at the store, I might have bought a porn magazine, but if I even see the latest issue of the same magazine, or a different one to what I have, I feel the compulsion to buy it.

The weird thing is, I probably might only ever view each piece once. 90% will probably never be viewed - just bookmarked under favourites, or stashed away. It's not like I am desperate for it - I just for some reason have a Pokemon policy for views of naked women: Gotta catch them all!

So why do you think this happens with porn specifically? And does this happen to anyone else?