Some days you eat the bear and some days the bear eats you.= You win sometimes and you lose sometimes. 勝つときもあれば、負けることも。 Some days you eat the bear and some days the bear eats you, ...and today isn't your day for bear meal.
Recently I was walking near an old man and a young girl. The girl was probably his granddaughter. He asked her if she would like to stay at his house a longer period of time. The young girl said no. Heartbroken the gentleman requested the reason why. The little girl replied that she didn't want to stay longer because her grandfather's farts were loud and smelly.