How could I collect that many things?

I lived almost my whole life in São Paulo, in the same house for 28 years before moving to Germany, what alone would be enough to help me accumulate a lot of possessions, but it is intensified by five years working with fashion; it made me collect quite a lot of stuff: clothes, shoes, accessories, etc. I also like japanese culture and all that comes with it, so books, magazines, dolls, toys, are all part of the things I love...
So I think it is easy to imagine how my room, and house were!
When I decided to study at the University of Heidelberg, I realized I would have to set a lot of my things free. I would not be able to bring too many things because I didn't have a place yet to stay and I knew I would have to carry my things up and down the city.
My goal, when openning my closet was clear, to make money out of it, so I loaded my Facebook page and blog with my precious things.
Funny fact is, before deciding to move, my requirements when tidying up my belongings were pretty different than the ones before traveling.

So here is more or less how I made my decision:

( Make up was not included because I was never addicted to that, I use the same eye shadow collection since 2011, same with perfum, always Bombshell or Funny da Moschino)

So in 2013 I donated or sold like 40 % of my belongings, I must confess the worst part was let my books and toys go, but I am sure they have new homes. I also got new ones in Germany, I finally got a Monchchichi to call mine!

Now I am moving again after 3 years living in the same room, and one more time a big challenge! I don't have as many things as before coming here, but I have now kitchen paraphernalia and other important things like a fan!

I tried to use Konmari's method, what makes me happy stay, but my question was:

I also checked some videos online about minimalism and organization, and I decided to combine everything: what makes me really happy, less is more, and to keep just one representative of the things I love, for example from my childhood I kept my Tiger from Disney, from my nerdy past my collection of Sailor Moon, from Hello Kitty a very special and limited edition and things related to Alice in Wonderland.
It is working, let's see what will be my next strategy when I move to another city.