Luck is a necessary but insufficient condition for success.

What does that mean? I am not quite sure yet, but some ideas:

Necessary - If one is successful, luck is involved, guaranteed. Someone somewhere else is probably doing something similar, with less success because of luck/circumstances.

Insufficient - Rarely are there anyone who achieve success purely due to luck. More often than not it is someone who got a lucky break, who then tenaciously capitalized the hell out of it.

Which means you can’t know which is the right bet, and there are no sure things. Even if you work hard and perform brilliantly, you’re still at the mercy of luck/probability.

A bit fatalistic, but I am not a fatalist. All this says to me is that, instead of pinning my hopes on one big break, or searching in vain for that sure thing, I must instead consistently work hard, work smart and work on different things. To couch it in probabilistic terms, bet consistently and diversely.

The nice thing about probabilities is that, as long as you keep working (betting), eventually you will win.