'Sorry, man,' he said. 'The joke should be: What do you do if your girl is peddling her BUTT all over town? Take her bike away!'

Now I had to laugh even harder than I had before, and even more hysterically, because this time his joke made sense.

I think I overdid it, to be honest, because he'd started to look at me oddly. I walked away, red-faced and exhausted.

It is very hard being British sometimes.

TUESDAY

I think if you're ever caught in the middle of a bank robbery, a good thing to do would be to compliment the robbers on their choice of disguises, because I bet no one ever thinks to do that, and it takes real guts, walking through town dressed as a clown.

WEDNESDAY

I think it must be really hard to be someone like Richard Reid the shoe bomber, because the next time he's at a dinner party and the conversation turns to jobs, he'll have to say, 'I'm a shoe bomber.' And then everyone will remember who he is, and he'll have to say, 'Look, I've done other stuff too, I'm not just a shoe bomber,' but all anyone will want to know about is the shoe bombing.

And then, worst of all, he'll know from the looks around the table that everyone will secretly be thinking that he's not even a very good shoe bomber, and whoever he was talking to will suddenly change the conversation to what they do, or mortgages.

That is the main reason I would not like to be Richard Reid the shoe bomber.

THURSDAY

I was reading one of those free newspapers on the train this morning and came across the I SAW YOU! column, in which people attempt to woo strangers they've seen on trains but not had the bottle to talk to. One of them said: 'To the scruffy guy in the blue jacket with glasses who was on the Northern Line the other day! Coffee?' I blushed. I had been selected. Noticed. I must've been. How many other men who wear glasses and are scruffy can possibly travel on Europe's busiest transport system? Plus - I own a blue jacket and have been on the Northern Line! This was spooky. But how would I explain this to my wife? I got my phone out in order to prepare a text, as I imagined she'd already seen it and would be distraught. I looked around the carriage, just in case anyone else had spotted this too, and wanted to catch my eye to share the news. There was a scruffy man in glasses sitting opposite me. He was wearing a blue jacket.

We scowled at each other, and then silently put our phones away.

FRIDAY