Denmark was one of the last countries to adopt masks. We didn't require them in shops, schools or elsewhere during our first, and by European terms, rather short lockdown between March and May. So my first time in a mask was probably on the Ryanair flight to Italy in late July. Anyone who tried a mask in Southern Europe at the height of summer knows they were rather hot and stuffy!
Since autumn, they've been increasingly required here, first on public transport and now in shops too so I always have one in my pocket and I can tell you that that might always be the case going forward, at least in my winter coats, because they are really quite pleasant indeed when the snow is driving into your face on a winter walk!