French Language

I have heard several times in my life that the French language is the same no matter where you are on the planet. So if a French speaking man from Vietnam, a French speaking man from Africa, a French speaking man from Paris and a French speaking man from Montreal were all talking, they would have no difficulty understanding each other.

Is it true? Sounds like bullshit to me

It is bullshit.  French in Quebec is virtually incomprehensible.

Of course, when a French person can't understand another French speaker he says the other person isn't really speaking French.