riverboat when you say there are big differences between private and public life what do you mean?
The most obvious thing is the way that politicians and public figures are much less scrutinised for behaviour in their private lives, because it is seen as totally irrelevant to their ability to perform their public/political role. Eg when current president Francois Hollande was revealed as having an affair with an actress a couple of years ago, the overwhelming response was "meh, so?" and everyone just continued as they were. Literally no one I talked to about it cared, there was no attempt to remove him from power, everything just carried on. If this had happened in the UK or the US it would have been a completely different story.
In terms of daily life for someone like me, I feel that the public sphere public - the street, in shops, in offices/restaurants, on public transport - is like a battlefield. The tendency is for people to act rudely, selfishly, aggressively. You have to be prepared to be the same to get treated with respect and get what you want. The same agressive, selfish people, when you encounter them in private, are likely to be lovely and friendly as anything!
Finally, there's more of a delineation between work and private life here. It's less common to socialise with colleagues than in the the UK - though I think this is changing actually, and it does depend on the company.