Well, in my school (in France) the explanation was the 'equal transit time' which of course didn't satisfy me at all (it took me a long time to get a satisfying

Well, in my school (in France) the explanation was the 'equal transit time' which of course didn't satisfy me at all (it took me a long time to get a satisfying explanation). So when schools teach this kind of BS, you can expect that the confusion will last a long time..