Kevin Systrom, one of the co-founders of Instagram, ended his NPR “How I Built This” with an interesting theory about life and success:

I have this thesis that the world runs on luck. The question is what you do with it.

Everyone gets lucky for some amount in their life. And the question is, are you alert enough to know you’re being lucky or you’re becoming lucky?

Are you talented enough to take that advantage and run with it? And do you have enough grit, enough resilience, to stay with it when it gets hard?

Because everyone gets lucky in minimal ways every week. You find a dollar on the ground, you get a break at work to work on a cool project, or you meet someone really interesting. The difference between people who succeed in the long-run and people who don’t is that optimism that you got lucky and now it’s yours to make awesome.

Kenny Rogers had a similar insight on a different level of success:

You’ve got to know when to hold ’em
Know when to fold ’em
Know when to walk away
Know when to run
You never count your money
When you’re sittin’ at the table
There’ll be time enough for countin’
When the dealin’s done