The dictionary describes Luck as: "success or failure apparently brought by chance rather than through one's own actions."
Some say it does not exist. There are thousands of motivational books and speeches that suggest luck is a figment of our imagination. They say to depend on luck is a losers mentality. There is certainly some truth to that. The proof is that the lottery has millions and millions more losers than winners.
So if luck actually exists, it is elusive, at best. But some things have an enormous impact on our lives, even though they cannot be proven to exist. One would be a little thing called faith. But there are others, too.
We all live with the effects of gravity, but we have no way of capturing it in a bottle.
In fact, unless you have been in space, you cannot escape gravity. Even space is subject to gravity. Black holes in space exert so much gravity they suck in light. But you and I can't touch, see, or smell a black hole in space. Nor can we touch or see gravity, but it most certainly exists.
As luck would have it, Earth has just the right amount of gravity so we humans can walk on its surface. The Moon is at the exact spot in relation to the Earth that it prevents our oceans from overrunning the land. The Sun is just the right distance from us that we can live without burning up. The Earth has just enough of a magnetic shield circulating around it to keep radiation from destroying all life. Earth's atmosphere contains precisely the correct amount of hydroxyl radical (OH), a chemical that plays a central role in the ability of Earth’s atmosphere to cleanse itself of pollutants, to keep our weather relatively stable.
Planet Earth is, so far, the only place in a universe of trillions of planets, that sustains life. I'd call that lucky for us. I didn't have anything to do with that, but I sure do benefit from it.