I have talked a little about not leaving your life to chance.
You should try as much as it is within your power, to be prepared for whatever may come into your life. Being unprepared is tantamount to leaving your life up to the winds of fate.
Sun Tzu stated in his classic book, The Art of War, that you should not rely on the likelihood of your enemy not coming, but on your own readiness to receive him.
If you are not prepared to make yourself unassailable to a possible enemy, it is not chance or bad luck that causes your misfortune when you are attacked.
It is the fact that you caused your own injury by your lack of preparation and awareness. You did not make yourself unassailable and therefore when some thug attacked you, you were injured.
Nothing happens by chance.
Everything has its cause and effect.
Both your invincibility and your vulnerability depend on you.
You make the decision.
There is no such thing as luck.
You may disagree and think that it was just pure bad luck that some thug picked you as a target, but you were the one who put yourself in a certain location, at a specific time, and on top of that, unprepared to deal with the threat.
No matter what the end product may turn out to be, you can be sure that there was some cause that preceded it. Nothing can exist without a cause; everything happens for a reason.
ps/smoh