What are the chances...?

In all the places I've spent a lot of time in my life, it's always been worth having a kind of social radar - just surreptitiously keeping an eye out for a familiar face. On the Isle of Wight, there was nothing surreptitious about it. Every other face was familiar, even if you didn't know the owner. At university it was similar, but still...there was the knowledge that there were a lot of people that I knew, simply knocking about the place.
When I first moved this close to London, I caught myself scanning the faces of the people in the carriages on the Underground, and internally smiled at my rather cute, small-town rural ways. I've stopped doing it now, which feels like a shame.

Considering that in the full span of your life, you've probably met more people than there are train stations in the UK, what are the odds on meeting someone you know whilst hanging around a train station at a busy time?

Not hanging around specifically in the sparse and barren hope that someone you know will emerge, magically, from the streaming suits, but, you know - hanging around for...uhm, some other reason.
I was walking past St. Alban's station last night (on my way to do something else - honest) and I thought, 'There must be loads of people I know who live in London and commute from towns like this.'
Thought gone, I was off and away past the warm yellow entrance to the station which was disgorging dark suited figures into the bluey night (sorry, got all 'Year in Provence' there...) and started thinking how chuffed I was that PaulyG thought I'd make a good Doctor Who...
"Stuart!"

Knowing the odds were against it, especially after such a theatrical train of thought, I turned anyway.
Someone I know. Longer hair since I last saw her, never seen her in a suit before either, so it took a second, but yes. Someone I know.

In the immortal words of Harry Hill...