I was born and raised in Toronto, but for the last two years I have been proud to call myself a Londoner.

During my time here I have tried every inch – short of adopting a phony British accent – to submerse myself in this brilliant city's vibrant culture and traditions because there's no other place more exciting on earth.

On Wednesday night, at my boss' drinks party in Charlotte Street – about a kilometre from Tavistock Square – I stayed out far too late and had one beer too many – because leaving the pub before closing time, as any Englishman will tell you, constitutes a bit of a snub.

Before I went to bed, I promised myself I'd pay off my sins by getting up early Thursday and hitting the gym before 8 so as to catch the tube in plenty of time to be at work by 9.15. When I woke up, my hangover told me otherwise. I ran to catch an Underground train, arriving at Brixton station, in south west London, at about half past nine.

The gates were shuttered and a crowd of about 50 milled around amicably outside. They were restless, but not angry. Pretty much everyone was fiddling with their mobile phones. One man in a pink tie was calmly bemoaning how late he'd be getting into the office. It sounds clich้, but my hangover probably saved my life. If I'd gone to the gym, I would have been somewhere under King's Cross when the bomb went off.

A phalanx of London Underground staff told us the station was shut and were calmly handing out leaflets showing all the bus routes into central London. They advised us to board a fleet of double deckers massing on the other side of the road, which many of us did. But they offered no reason why the station was shut.

Aboard the bus, it soon became apparent something was seriously wrong. The mobile phone networks were jammed. As we crossed Vauxhall Bridge into central London, those lucky few who were able to place calls talked in staccato bursts: "attack" and "Liverpool Street" and "terrorist". Everyone aboard was now clearly agitated, but no one was really mad.

When the bus got to Whitehall, near Downing Street, we were unceremoniously dumped into the street and told no bus services were operating. It took me 45 minutes to walk to my office near Oxford Street, in the heart of central London. On the way, I passed three people who were miraculously getting phone service, offering their handsets to complete strangers so they could contact friends and loved ones.

As the day wore on, the predominant mood was not anger, nor revenge, but sadness. There's a tiny shop wedged in the myriad alleys behind Goodge Street where I often buy lunch. Even though my accent sticks out like a sore thumb, the man who makes my roast beef sandwiches never fails to ask me how I'm doing and when I go in with my girlfriend, always cocks his eye and asks why I don't pay for her baked potato. He always makes me feel at home. Today, his silence said it all. But the queue for food stretched out the door, just like it always does.

As the end of the workday loomed, a light drizzle lifted and men and women in impeccable dress strolled down the streets. The pubs on Goodge Street were packed once again, even though the husk of the now-infamous blown-up bus was still smouldering a half-mile to the west. There was a palpable sense that what these Londoners needed most was a return to normality – not to ignore what had happened, but to show whoever did it that their lives will continue to be lived as they always have.

London is a city shaped by conflict: it rose, transformed, from the ashes of the Great Fire; it rebuilt itself with astonishing zeal after the Blitz. London will learn from this outrage and emerge stronger than before. So I took a leaf straight from London's book, and when the working day was done, I headed straight for the pub.