Dark Alley, Deep Message

Relieved to arrive in Leamington after a challenging drive up the country through bands of wintry weather. Arrived at wrong time to park free on the street which led me to encounter this message on the exit from the multi story car park. Could be interpreted different ways....when did humans stop being great? Before civilisation began? Sometime shortly after the Enlightenment? When they voted for Brexit and Trump? Or maybe it was just promoting some band I never heard of... and I’m over thinking it!!