Why? I dont need to answer that. You already know to Survive!
But why a walking stick? If youre a big tough guy, 4th Dan Black Belt in karate or other martial art, you dont (really) need a walking stick to defend yourself. Unless your big interest is in fact stick fighting, sutekki-shin-jutsu. When you would always carry one, as I do, for the fun (and the Hell!) of it. Im never without my Stick and my Dog. (What about my wife?)
But what if you are a young athletic cyclist or road runner? This is a bit more (much more!) difficult. Obviously you cant lug a walking stick around. A kara-tetsu, now thats different, sensible and practical. So a stick is not for you, mLove. My advice here is breathe more oxygen, hold on to your karatetsu and run even faster. Make sure you can outpace that mugger.
Now you football kickers, rugby smash-downers, tennis hitters, heres your chance to walk through a park without fear! Without trembling as you walk past those bushes. (Am I exaggerating? Of course I am!). I KNOW you dont need a walking stick to defend yourselves. You could just spit and knock a mugger over. We all know that.
But a weapon in your hand is better...