I would also note that if you come in to an potential employer who asks if you are a certified forklift driver. and say "I have operated a forklift, pretty much like what you have here, for many years, but I am really sure that the certifications have to be site and truck specific and must be provided by your company, so the previous knowledge I have comes with me, but you have to provide the current and proper paperwork", after they "check the facts" then they will/should consider your knowledge of forklift certification as more valuable than the piece of paper of a certification.