The impulse to escape is an adolescent one. Remains so, as does our desire for urgency in doing so.
While letting casually slip news of impending exit to fourteen year old tearaways, they asked what I would be doing with my time once I leave. Explaining that I was going to travel the world for a time, do some VSO, reach for some further horizons, their reaction was as simple, honest and directly logical as we ever expect from pre-adolescents.
"Why would you do that? Isn't that a waste of money, Miss?" asked Tommy.
Chezney was unperturbed, eager to avoid any writing, "No way, if I had the money, I'd go to Kingston, Jamaica again. Everything is really small there. They have chickens."
"But if you think about it, Miss," persisted Tommy, doodling a cartoon of King Krull on his 'missing persons' poster, "that's going to be a waste when you get back. Where are you going to live? I would spend the money on finding a house."
I explain that I'm likely to be away for quite a time, that I haven't the money to do both things - buy a house in the property hot house that is London, and travel.
Thali's ears prick up, and he invents a question to make me move across and exlain to him where I'll be going. "So you're just going to waste time, Miss?" His eyes widen in near outrage.
I think about it. Yes, I suppose so. I suppose it is.
Somehow a life without hourly bells, sugar highs and tannoy announcements looks rosy with this new label.
I try to pacify Thali by explaining how I'm going to visit his home country.
He shifts excitedly in his seat, tells me a story of how he's been too scared to go back since a time when he was five, seeing a snake entwine itself round his mother's ankle and grip.
"Don't go there, Miss, it's horrible." Big eyes. "They have snakes!"
I agree that spiders and snakes are to be feared, and jungle expeditions frowned upon. South East London possesses no such dangers. The predators here, and the web they weave to snare these boys are of quite a different order.
"But if you think about it, Miss, that's a really really long time to waste. Just to waste it."
One final try.
"You see, Thali, time is different when you get to my age. For you, a year is a long time. It's a whole year! It's forever. If it's just before the holidays, a week takes forever, doesn't it?"
He nods, pen raised and forgotten above the poster.
"When you're an old old lady like me, you'll find that you've lived a very very long time, and it makes things seem different. For me, a year goes by just like that." I blink, snap my fingers. "In an instant. Was that a year? I didn't notice."
"For people who are very very old, like me, five years is nothing. When you're old, when you're a grandpa, and all your grandchildren are gathered round your knee, you'll blink, snap your fingers, and they'll be older. Just like that. And you'll say 'my, haven't you grown tall?' Because five years has passed and you didn't notice. Didn't notice at all."
Thali's eyes light up, middle distance, at the little grandchildren soon to be clustered around his knee.
My eyes light up at the idea I'll be wasting my time.
We both smile. Just a little.