What is LUCK?

I define LUCK as a “wildcard” that we use to justify something that does not logically make sense. LUCK only comes into play when things don’t go as expected. If all the things in this world had gone as planned and expected, the word LUCK would have never existed. Lets say you work very hard for something; you definitely expect great results. If the result is as expected, you don’t even bother sharing the credit with the word LUCK because you need to. You work hard; you get rewarded, that’s logical enough. But when you work hard and don’t get the best outcome, or something goes wrong; that doesn’t logically make sense. That’s when the word LUCK comes into play. Now, you use the so called “LUCK”, your “wildcard” to justify something that didn’t logically make sense.
Example: You study real hard and prepare for an exam. You go take the exam and you do well. You never consider yourself lucky. You don’t even think about LUCK in that scenario because things worked as planned and you think you deserve it. But lets say the opposite were to happen. You don’t study at all and then you go take the exam and you still do well. That logically doesn’t make sense. You can’t really say you deserve. Now is when you use your wildcard LUCK. You justify this scenario by telling yourself that you got LUCKY.

I wanted to know what everybody's perspective on LUCK was....please share ur thoughts...