The whole point of using on in French is that it's ambiguous. This sentence is used so that we don't point anyone in particular. We, you and one should be correct.
I am french and I know that in french "On" translating in english " we" but not "you" it's a very bad question. I am sorry if my comment it isn't good because my english isn't perfect.
Si jamais quelqu'un prefere voir ce commentaire en francais (if a people wants see this coment in french) Le voici : "Je suis francaise et je sais que en francais " on " se traduit en anglais "we " mais pas part " you " c'est une tres mauvaise question. Je suis desolé si mon commentaire n'est pas bien parce que mon anglais n'est pas parfet"
Yes, "on ne sait jamais" is a typical example of a general address which translates to "you never know". This "you" is not addressed to one person or several people in particular, but a general address.
Sitesurf - I have been unable to find the 'Today is not my day' thread in D/L. I did however receive your response to my query on it in my email. I wanted to say a big thank you for your excellent reply which is really helpful. (I am visually impaired, so apologies for my ignorance of how to master this technology!)
"We never know" is accepted, probably because this simpler formula is more common.
In my head I translated it as ambiguous someone not know never. I actually put down "No one ever knows." It was marked as wrong. Any input as to if I should fight for this translation.