Originally Posted by
I-Like-To-Bike
I lived in Germany for 10 years (1986-91 near Zweibrucken, 1997-2002 near Heidelberg) and vacationed in The Netherlands at least once every year while living in Europe. I never saw anybody commuting on a workday while wearing lycra or cycling specific clothes. I did see groups of lycra clad cyclists on the weekends riding together outside of urban areas in both Germany and NL. The only cyclists I ever saw wearing helmets in NL were riding pannier loaded touring bikes and were speaking in English. Occasionally I would see cyclists commuting on a workday wearing a helmet in Germany but they were the exceptions.
My bike in foreground at the Heidelberg Main Train Station Front Entrance. I still use the same bike daily.

I think that's consistent with North America. The number of people commuting by bike in most NA cities is in the 1 to 5% range which is significantly lower than many European cities. Of the NA commuters only a small fraction would be seen wearing lycra.
Because Europe is older and the population density higher, commuting distances in general are shorter. Short distances make it practical to commute in work clothing. In NA, longer (20+km) commutes are more common and proper cycling attire is more practical.