A bigger person? What if they know how to fight? What if there are two of them? What if they have a suit of medieval armor on? These are all serious and reasonable things to worry about. Here’s a way to contextualize it: Right now, there are about 8 billion people on the planet. On a scale of zero to 8 billion, you are somewhere in the middle. “This,” (whatever “this” is) will work against some of them, and not against the rest, as shown in the diagram below. 0 ←–––––––– YOU ––—–––––→ 8,000,000,000 Every time you train, you move a little bit further to the right, and the further you go, the more likely that if you DO have to fight for yourself, if you DO have to use “This,” against someone, it’s going to work. Ultimately we won’t know until it happens; what we can do now is prepare ourselves as best we can, and raise the odds in our favor by training hard and consistently.