Half the good jobs people have started out as covering somebody else's shift. The opportunity didn't announce itself. It looked like an inconvenience with bad timing.
Open-mindedness is mostly a delay. Not saying yes to everything, just not saying no in the first four seconds, before you know what it is.
The cost is real. Some Tuesdays get spent on a pottery class that leads nowhere. That's the price of a wide net, and the net is how the rare thing gets caught.