Four years ago when I was a boy of 11, I got into the biggest trouble as a kid. It was a Saturday morning. Both my parents were out, leaving me and my 10-month-old sister home alone. Anyway, my sister was still asleep in her room. In fact I had the house to myself. I decided to do some drawing. Soon I gave up. Nothing was on TV, so I felt bored and touched the candles on the shelf ...I had an idea! What would happen if I set fire to some kitchen paper? Well, of course it went on fire, but it wasn't the tiny flame  I'd expected, and I couldn't blow it out. I threw it on the floor, and then luckily got my dad's boots  and _ it _ . I thought I was safe until there was a huge hole in my room. When my mum came home later, she smelt the smoke immediately. She dropped the shopping bag, luckily for me, over the hole. I thought this meant she would never see it. However, after running round the house checking for a fire, she of course picked up the bag and saw the hole. Next I was grounded  and in trouble for months. Even worse, the hole was still there, reminding me of what I did. . What's the main idea of the passage?
It's difficult to put out a fire. The boy didn't look after his sister. The boy made a big trouble when he was 11. Don't leave children home alone while shopping.