Say they get that knife/gun off you and use it to stab/shoot a kid... would you still have the same opinion. You may think you're a strong man who nobody can touch, but let me tell you, however big or strong you are, carrying a knife/gun shows your weakness.
There's so many possibilities that could lead to other being killed because of ignorant people like yourself. They shoot you with a tazer/gun and take your knife/gun off you, you haven't just killed yourself, but most likely some other innocent person.
No point in arguing, people like you always think your right. You want to try being a teenager that's growing up in London, then you'd learn carrying a knife/gun won't stop someone from sticking a bullet in your head when they see you've got a gun/knife.
I guess carrying a knife/gun makes you feel like a big man, all I can say is I hope you're the one that it gets used on instead of some kid or innocent person somewhere down the line.