I agreed to meet the others at the same patisserie where we had enjoyed breakfast earlier in the day. A round of cakes would set us up nicely prior to catching our flight back to the UK after this US trip to celebrate the GCSE results of AF and her friend LA. In the meantime, I wanted to visit the Robertson Public Library, installed on the top floor of one of New York’s tallest skyscrapers.

Even after a week in the city I was still unused to the American attitude to small change. At the foot of the escalator that led up to the library I found – once again – piles of discarded coins, and even a couple of ten dollar bills. I set about collecting up the cash for later use. I thought nobody would notice my scrambling around on the floor gathering up the money, but when I reached the top of the building I came across the security guard’s desk and his array of CCTV cameras. He knew all about my filthy little shrapnel secret.

Despite this, the rest of his intelligence on me was hardly impressive. He wanted to bar my entry to the library on the grounds that there were no professional staff on duty at that time of night. He refused to let me through because I would be unable to navigate the collection on my own. I pushed straight past him with every assurance that I would be just fine.