First of all, I doubt that anyone ever has "forgotten everything" -- certain learning experiences just burn the details into the skull forever ...
... Heck, I still have details from 6502 assembly, 8088/80286 assembly, turbo pascal, prolog, etc. which I haven't used in over a decade.
If some of what you learned in the previous life seems applicable, maybe starting with a refresh is easier that learning a completely new language. Programming concepts and best practices are generally independent of the language.
Henry