Back in 2000 -- back before I had a blog, so it wasn't recorded at the time -- a boy my age tried to con me and steal my mobile phone.

I lived for six months in 2000 in Streatham, London, which at the time was a pretty dodgy neighbourhood, and caught the train into central London through some even dodgier bits of south-east London like Peckham and Dulwich. It was at one of these stops that the thief got on board, taking a seat opposite mind. He was dressed normally for the area -- track suit bottoms and white sneakers. He was very pale and quite spotty, which was also pretty standard.

After a few minutes of sitting in silence -- what I later realized was a very carefully timed move -- he asked if he could borrow my phone to call his mum, who was supposed to be meeting him at the station. He didn't know where she was going to be. I hesitated, and he said "it's not like I can run off with it, we're in a train". I conceded the point and handed it over. He made a call and proceeded to talk, and just then the train pulled into the station.

He got off the train still talking, with me following him, slightly irritated. I kept expecting he'd spot the person he was looking for and end the call, but he didn't, he just kept walking towards the taxi rank at the exit, all while appearing to be talking to someone and looking around for them. I grew tired of it and tried to grab the phone away, but he had a firm grip on it, and shot me a glance like I was the one being unreasonable.

As he reached the exit of the station he finally made a dash for it. I had been half-expecting it by this point, so I immediately ran after him: I couldn't abandon the phone, it was enormously valuable, as a piece of equipment but more importantly as the source of the phone numbers of everyone I knew in London -- I didn't have a backup, and for lots of people their phone number was the only contact information I had for them.

London bridge station exit is above street level in places, so he ran over a pedestrian crossing that went over the main road and started running down the stairs. Realizing I was losing him, and desperate, I launched myself down the stairs after him, hitting him in the back and knocking him to the ground. There was a lot of untidy scuffling, but eventually I wrenched the phone away and he ran off -- I think he was more surprised than anything; I don't think anybody had gone to so much trouble to get back a phone before. It was also completely out of character for me -- I'd spent five years on the losing end of physical confrontations at high school, so actually coming out with my phone was a result.

But my naive, eighteen year old's view of London as a safe playground was cruelly shattered. I was careful with my belongings and never lent my phone to a stranger ever again. It was a shame, but one of those things that happens to everyone eventually.

So last night when I was making my way home, and I saw a pale and spotty youth, complete with track suit, sit opposite another young man and ask him to borrow his phone, I was certain I knew what was happening. As before, the request was innocently made. As before, the call went on surprisingly long. As before, the train pulled into the station. I was between the youth and the exit, so I positioned myself subtly, ready to stick out a leg and trip him up when he made a dash for it.

And then the youth handed the gentleman's phone back to him, and quietly got off the train. And I felt a little bit of my faith in humanity grow back, a decade after it went away.