In a quiet, affluent, middle-class residential area, it has long been 'normal' for teenagers to have cars, to talk as loudly as they used to when they were little kids in the playground, and to schedule parties during their parents' absence and without the parents' knowledge - it's as inevitable as small children leaving sticky fingerprints wherever they go. In my experience, parents know all too well that despite there best efforts, teenagers are slow to learn that the privileges of autonomous adulthood have to be balanced with responsibilities, and a lot of this learning only comes with maturity.
Our 17-year-old son had a party while we were away, and of course we'd set some ground rules, and of course more people turned up than he'd been expecting, and of course things got out of hand. Even before any neighbours might have complained, our son himself phoned us to say he feared we were going to be sent a massive bill from the local fire service after he'd called them to report two girls being locked in the toilet after losing the key ... By the time the fire engine arrived, the girls had unlocked the door, so he'd succeeded only in wasting the fire service's time. Luckily we were able to explain that he'd been genuinely concerned - he was inclined to be gullible - and the call-out charge was waived. But our son had learned that lesson, and didn't even try to have another party - he was too embarrassed. Similarly my brother-in-law likes to recount that on more than one occasion he had to pick up our 14-year-old niece from A+E after an evening of immoderate clubbing. Luckily, like most people, they have grown into responsible adults who know their own limits and are valuable members of society. The teenage years can be a minefield for parents and neighbours, and all too often for the young people themselves, but I'd rather have a few sleepless nights than read about teenagers taking four friends out in their new car t celebrate the end of A-levels, and wrapping it round a tree, as we read about so often in the papers, even if it hasn't happened to any of us.
All this, of course. doesn't make it any easier to bear a sleepless night in a heatwave, to the accompaniment of a pulsing beat that you haven't chosen to hear - you have my sympathy!