"Oh Britannia, summer of '45"

The story:

My girlfriend is much, MUCH more musically inclined than I will ever be. Before meeting her, I had spent several years looking for this song, but since I never knew who sang it, or even how it sounded (to describe it, I would hum the tune, mumbling along until I shouted the one line I THOUGHT was the real one..). I would ask co-workers, family, friends...but nobody had heard of this song. Then Cornershop had an appearance on Much Music singing this very song. At that moment, I realized I was quite the fool.