The moment I actually faced the Mona Lisa..

The Louvre Museum in Paris, where the Mona Lisa is! One of the things I was most looking forward to in Paris was the Louvre Museum, but I almost couldn't go because I didn't make a reservation. However, I found out that if you book a tour, you can enter through the tour entrance with the tour company, so I immediately signed up for a tour! For those who, like me, failed to make an individual reservation, I recommend joining a tour! Also, it was much better to listen to the guide's explanations and see only the important works rather than going alone. I would have regretted it if I had gone by myself..