The pronoun "man" is more common than the pronoun "one" is in English. It is approximately the same, i.e. used similar, however, it's a bit different. "One" sounds closer to "someone" whereas "man" is closer to "human", i.e. "anyone". A typical sentence would be: "Man kann nicht sicher sein." (= One cannot be sure.)
It is neither wrong nor a bad style to use it in cases where the third person singular isn't specified. In English I would probably use "you" more often in such cases: "You cannot be sure." does not really specify you as a person, rather "you=one" as any person. In this sense "man" is more common.
But to use it as a synonym for "I" is ridiculous and bad style. And it's frequently used in interviews if people speak about themselves. They refer to themselves as "man". I hate it. And the only reason I see is, that they create distance between them as a person and that what they did or did not. "Man hatte kein Halt auf dem Feld." (= One hasn't grip on the pitch.) ***, you idiot had the wrong shoes, that's all. Don't blame the weather and do not speak of a third person "man", if you want to cover your own stupidity.
"Man sieht sich!" (= See you!) is another example. It could mean anything, from "I hope to see you again" to "I hope to cross the street in time next time I see you coming". It's non-binding. Stick it where ...
