You left one out doc, Desperation!
I was scared to death of this big guy, and I admit that if I had two good legs under me, I may have just cleared off out the side door as he was coming in the front. But I don't run so well, certainly not going to outrun some 28 to 30 year old. It was the cornered rat syndrome. Cat corners a rat, even a rat will rear up to try to bite back. All I had going for me was the Opinel, and my making this guy very clear on that I know I'm no contest, and I may die of brain damage after he hits me in the noggin, but by the time my family have to make the decision to shut off the ventilator, he'll already be in the ground. That's all you have left as a senior citizen in a corner. We're already close to the end, may as well take him with me for the trip. Us seniors may only have 5 or 6 years to loose. He has most of his.
Never back someone into a corner who has very little to loose. Maybe that's why a lot of us old farts are curmudgeons walking around in an angry mood. We're so much closer to the end than the beginning, we're mad about it.