A large foundation for the belief in critical periods for language are based on Genie, a feral child who was entirely unable to learn a spoken language despite significant efforts. Today, she can use some sign language but cannot speak.
https://en.m.wikipedia.org/wiki/Genie_(feral_child)
So the answer is largely believed to be: No. You cannot learn a spoken language if you missed the critical period.
It's also literally impossible to test/study ethically, so nobody actually knows.
When cocaine usage first exploded, it was almost entirely in "laborers, youths, black people, and the urban underworld". Most of the early history of its usage is associated with non-whites and lower class peoples. Making it illegal worked for a long time until the cocaine boom happened and then it became popular with disco and rock, but again, still mostly used by non-whites. It wasn't until crack became a thing that the racial divide became more clear - rich whites got the clean cocaine, everyone else got addicted to crack.
https://www.degruyter.com/document/doi/10.12987/9780300255874/html
The switch to being heavily used by the rich white class is a "relatively" recent development.