Hi. Planning a trip to London for next Spring. I noticed an informative thread in the Paris forum, entitled "What do you wish someone had told you?" (tripadvisor.com/ShowTopic-g187147-i14-k47347…). I thought I'd post the same question about London: What did you discover you wished someone had told you before your first trip? Did someone give you advice that you found particularly helpful or useful that you'd be willing to pass on? Thanks in advance!