Its not a chance for you to show off remember, the whole point of an interview is to see if you can think on your feet and how you react to a bit of pressure. Everyone who was there must have prepared a massive spiel about how much they love flying, and how much they love BA etc so they are not going to learn anything about you by letting you waffle on about these topics.
Just wait till Wednesday, you've probably done a lot better than you think...