The effect of repetition

Now, on TV, usual advertisement are rare because companies decrease the number of times they appear public due to the earthquake. And instead of that, same advertisements from public non-profitable organization on air all day, intended to make the people have moral.
Since we see that ads so many times, we're fed up. But I like one ad that is something like this.

遊ぼっていうと遊ぼっていう　 If you say "Let's play", and the other says "Let's play"
ばかっていうとばかっていう　 If you say "you're fool", and the other says "You're fool"
もう遊ばないっていうともう遊ばないっていう　　If you say "I won't play with you", and the other says"I won't either"
そして、あとで寂しくなって　　　and later you get sad
ごめんねっていうとごめんねっていう　　and when you say "I'm sorry", and you'll hear "I'm sorry"
こだまでしょうか？　いいえだれでも　　Is this just repeating? no, this occurs to everybody

Pretty nice ad that made me aware the simple notion, be nice as you want the other do to you.
and this ad reminds me of my old memory.

When I was 10 years old, and that started from the lunch time, in Japan lunch is served for everybody and we eat together, and on that day, there was watermelon, and my closest friend ate the pillar, and I felt challenged and so did I. and this competition continued.
After that, since I was taking part to take care of animals that we had as a class, my friend suddenly ate food for fish and turtle, and so did I. I remember that wasn't that bad, it tastes like fish. And finally, on the way to home, he ate leave, and we started arguing. I kicked him, saying really bad to him. He is really kind guy, and just resisted.
But on the next day, I went to school feeling strange, I didn't go to school with him that day, at school, he came to me and said "I'm sorry", and I felt completely sorry since I was completely evil, and we friends again. Even now, it's been 10 years, we're still best friends.

You see, this is the effect of repetition.