It's just so... civilized.
Everyone glides along at an even pace. Old folks, business people, students, moms with tots in tow. It's one of the most enjoyable experiences to be had. And safe. Helmet? Never even crossed my mind. Over here in Montreal? Don't leave home without it. That's the difference. There is no antagonistic relationship between cars and cyclists there. If anything, the bike is king. Everybody does it, therefore it's deeply ingrained in the national culture and respected as a daily form of transportation. Not just a leisure activity or a cheap way to get around for people who can't afford a car. We still have pretty far to go before urban transport gets this evolved.