Is it normal to pick up stuff of the ground

Hi there lets just jump right to it, I pick up stuff from the ground and keep it. It can be anything between a simple metal nut or bolt to radios and umbrellas. And its not all from the ground i search through trashcans and recycle bins.

I take these apart and use the parts to make an assortment of weapons (mostly the ``stealth´´ kind of weapon like an all plastic hidden dagger made from a soda bottle and a garden light). I think its a hobby of mine but im not sure, And the gathering of materials could be a form of stress behavior, since when in an stressful period i gather more stuff than usual and the making of weapon is that i REALLY like weapons especally the blade kind and need to get the junk i collect of my hands.

Some of my friends find it fun and interesting and some scary and disturbing.

So if you do these stuff to or have an opinion an comment would be appreciated.