1. People will pose next to anything. A light in the crypt of the Pantheon next to the tomb of great writer, Voltaire? No flipping problem. The only rule was to be quiet and respect the building anyway. Hmmm.
2. You will almost get run over at least twice a day and therefore appreciate your ability to cross roads expertly in England.
3. There are lines on the metro which will remind you of specific ones on the London Underground. The seats are less cushioned but the stops are much closer together so I've not figured out which the better deal is.
4. Visiting when under 25 is fab because you get free entry into most of the top tourist attractions.
5. Brie and baguette works perfectly with breakfast, lunch and dinner.