Guns & knives - swords & muskets - these sorts of things go together. It's not a medical condition. If it is a medical condition then it's been a medical condition all through our human history.
We accumulate a variety of good and effective defensive weapons of whatever era we live in.
The sword & the dagger. The lance and the sword. The 6 shooter and the Bowie. The derringer and the boot knife. The machete and the blowgun. The spear and the boomerang. The knapped flint knife & the club. The crossbow & the short sword.
The armies of the world do it and the warriors and the soldiers in the armies do it.
People do not "DO SERIOUS BATTLE" with only one weapon.
They gather up effective deadly weapons so that they will have them if they need them.
It's a Human Condition and not a medical condition.
It dates back to when we were Hunter Gatherers and the small tribal groups stored food, weapons. herbs, furs, etc. To have MORE food and More weapons and MORE of every necessary thing insured survival in a very harsh and unforgivng environment.
It's part of our ingrained human survival instinct.
It is a condition that is as old as we are as world people.
That is my opinion on it.
MODERN people who do not accumulate weapons accumulate money as a substitute for weaponry & they "BUY" their daily survival with money.
I could go on and on about it all...but, basically that is why we accumulate defensive tools.
So...if you want another knife then go get one. It's normal.