Zizek, as usual, is saying something facile but with flowery language to make it seem insightful, but the idea that in order to understand his culture a man must leave it and view it from the outside, the same idea Zizek is sharing here (amid sniffs) is an idea that goes back at least as far as Buddhism, as it is present in the story of the youth of the Buddha.
Zizek is very ironically an ideologue himself (a "Hegelian" in his words) and as such his version of the story only contains half the lesson -- that culture, which he calls ideology because he seemingly refuses to truly understand what ideology is, lest admit he is an ideologue, can blind members of that culture to certain things, but without addressing that culture and ideology have positive aspects as well.
The man is a neverending font of faux insight and obscurantism posturing as wisdom and this quote is no different from any other.