题目内容：

    When our son Peter was twelve, the new bicycle he had received was stolen. Owning a bicycle was big fun to our children when they were little. They spent hours and hours, day after day, on their bicycles, riding up and together as a family a lot. Bicycling was a great way to get the kids out of the house and into the fresh air without spending the money.

When Peter and his sister went outside for a morning ride, he discovered that his bicycle had been stolen from our backyard. He couldn't believe that someone would do this.

He got a large piece of cardboard, painted a sign begging for the bicycle to be returned, and tied the sign to the letterbox. The following morning, when I went out to collect the mail, I found a white envelope with the magical words, "Buy yourself a new bicycle". There was a $ 100 banknote inside.

We were very touched that someone had the heart to do this. We'd never been able to thank the person but we guessed that it may have been one of our wonderful neighbors. Peter painted a big "Thank you!" on the sign and we left it outside for a couple of weeks afterwards, hoping the kind stranger would drive down our street and see it.

Peter was able to own a new bicycle again. As the years went on, the bicycle became older but remained just as important as before. Now Peter is 25.

All these years later we are still thankful for the stranger's kindness. We were a young family with three little children and it meant a lot to us. We still talk about it and, even now, wonder who the kind stranger was.

根据短文内容，回答问题。

1.What did Peter often do when he was a child?

2.Where was the bicycle stolen?

3.How did the family feel after someone had the heart to give them the $ 100 banknote?

4.Why did Peter put the 'Thank you' sign outside?

5.Did the writer and the family remember or forget the stranger's kindness?