Many people think that Holland has always been covered in bike lanes. It hasn't, but that never stop the masses from bicycling.
As you can see in the video below from 1950, before there was a bike lane in sight, bicyclists were extremely abundant on the streets of Amsterdam.
As it is today, people of all sorts biked for transportation back then. In one segment, the videographer focused on a bicycling nurse (with a sort of odd joke, imho). Here's a screenshot of the young nurse casually biking along:
You can also see in that screenshot that, long before cargo bikes started to get hip in the US, they were in common use in Holland.
In the next screenshot, in a suit in the midst of traffic, a man bikes along with his dog:
As they do today, people rode on the backs of bikes, and toddlers and babies often rode on the fronts (as well as the backs):
With bicycling such a big part of everyday life, they apparently had an annual race between butcher delivery boys in Amsterdam.
Is there a useful point here? Yes, I think there is. One of my graduate professors in the Netherlands was fond of pointing out to visiting students that bicycle infrastructure didn't precede mass bicycling in the Netherlands. It was the other way around. While we often think that bicycle infrastructure is critical to bicycle growth, that's not the route the Netherlands took. It had mass bicycling and then it had great bicycle infrastructure.
With the speed people drive today, and with a general lack of awareness and concern for bicyclists in North America, I do think that good, protected bike lanes are critical. But I also think that a motivated citizenry that wants to take back its streets can do so without the infrastructure coming first. There are many ways to build a culture of bicycling in your community, and through that you can drive the expansion of bicycle infrastructure.
And one key to that, in my opinion, is making bicycling something that you do without any special clothing or style. Biking should be like walking, something you do in your normal work clothes, dress clothes, or casual wear. Here are two final screenshots showing the normal clothing of 1950 Dutch bicyclists:
Via Bicycle Dutch