unexpected thing
In everybody’s life, there are some unexpected thing happening. If that was good thing, we would call that good luck, otherwise bad luck.
Sometime, even though you planned very well to do something, always there was something unexpected happening. You sent a letter by express. But the person who conveys that does not hurry up as you expected. And then your plan was gone.
You are waiting for a person who was supposed to arrive at the place in time, one hour, two hour later, nobody came.
Somebody are really lucky, who were born in rich people’s family and need not to do hard work in their whole life but live a luxurious life.
Some people was born in poor family, whose life was full of hard thing. But can you say that born in a poor family is bad luck? We could not choose our parents and country.