"That's what I thought at first too，" the first sailor said， "but it turned out to be good luck... As soon as we took the sails down to fix the masts， we were hit by a squall so suddenly and so hard， it would surely have blown us over if our sails were up at the time."
"How lucky！"
"That's exactly what I thought at the time， too. But because our sails were down， we couldn't steer ourselves， and because of the wind， we were blown onto a reef. The hole in the hulls was too big to fix. We were stranded."
"That is bad luck indeed."
"That' s what I thought， too， when it first happened. But we all made it to the beach alive and had plenty to eat. But now here's the real kicker： While we were on the island whining about our terrible fate， we discovered a buried treasure！"
As this story illustrates， you don't know if an event is "good" or "bad" except maybe in retrospect， and even then you don't really know because life keeps going. The story's not over yet. Just because something hasn't turned out to be an advantage yet doesn't mean it is not ever going to.
Therefore， you can simply assume whatever happens is "good". I know that sounds awfully airy-fairy， but it's very practical. If you think an event is good， it's easy to maintain a positive attitude. And your attitude affects your health， it affects the way people treat you and how you treat others， and it affects your energy level. And those can help pave the way for things to turn out well. A good attitude is a good thing. And a bad attitude does you no good at all.
So get in the habit of saying "That's good！". Since you don't know for sure whether something will eventually work to your advantage or not， you might as well assume it will. It is counterproductive to assume otherwise. Think about it. If someone ahead of you in line at a store is slowing everything down， say to yourself， "That's good！" They may have saved you from getting into an accident when you get back in your car. Or maybe， because you slowed down， you might meet a friend you would have missed. You never know. The truth is， life is uncertain. And even that can work to your advantage.