Not my own story, but the reason I started to carry a knife regularly. I have always used a knife as long as I can remember. I got my own swiss army knife in grade 2 (7ish?) but played with my dad's knives as earlier than that.
Anyways, when I was young I would generally only a carry a knife on me when I was planning on using the knife. So if I was going into the woods to go cut some trees and carve some stuff Id bring my knife. Other times it would stay in my favorite stuff drawer.
When I was young, I think around 12, there were a lot of those 911 and rescuer type shows on TV. I always watched them with my dad before bed. Some interesting stories and such. Anyways, one of these stories really touched me and changed my knife changing habits forever. In this one episode, a women gets rear ended and her car catches on fire, and her seatbelt is unfortunately jammed. No one has a knife including the cop on scene. Sadly the women does not make it--she effectively burned alive (although it doesnt show that on the show). From that moment on I swore that I would always carry a knife on me, and have ever since. I even carried a small little blade in school, although it never left my pocket. It wasnt some super quality blade, but it was there in case I needed it.
I may never need to use my knife to save someones life, but I like to know that I could if needed.
And thats my knife story.