This is one of the biggest reasons that restrictions on speech, let alone ones that seem to be so vague, are so very dangerous. They can be used, and abused, to great effect whereas their net positive effect is perhaps harder to gauge. In the US we do not have many laws that are so open to social interpretation, but with those that we do, we already see regular lawsuits well outside the spirit of the law that individuals hope to win by force of legal and persuasive prowess alone. Even if France might have a more mature legal culture, who's to say such things will not change?
This is why I think when looking at laws, we should not see things through the most positive and optimistic lens, but through the most critical and cynical lens. The reason is because that lowest common denominator is shown, time and again, to end up being what the law will be disproportionately used for.
Wasn't this always the biggest problem: People not knowing. I also didn't get any problems and I'm close to your age - but I listened to a lot of stories from my wife in which people were doing things that may be considered offensive or even harassment, and without knowing.
All the big metoo cases, for example, are not people who didn't know. They are people who were activly predatory over many years. The accidents aren't what are being targeted here. It's mostly men activley and knowingly abusing the fact that they can get away with it.
The first you learn of it is when the cops come up and interview you.
You indicate ignorance and also that you think the woman was a shit for dobbing you in.
You indicate ignorance and also deep remorse - you're genuinely hurt that you harassed this woman and potentially several others.
You indicate ignorance and feign deep remorse - you actually think the woman was a shit. You bring up sex with strangers again and the police see that you have form.
There's a difference in what's going to happen in these cases. The fact that the police think it's worth investigating a report of a crime doesn't mean they'll react in the same manner to different circumstances.
That's the key to your comment. You cannot ever know for certain if your conduct offends someone. Some people get offended if you look at them the "wrong" way. I don't think you should be fined for accidentally offending someone.