Locked in the stairwell of the Met

The Metropolitan Museum of Art is unbelievably huge and crowded - especially on a Sunday. Once admitted, we set up a meeting point - one p.m. in the gift shop.
I scanned the exhibit of modern photography, the 17th, 18th-century European wing and next the 19th, 20th century section where you can drink in more Degas, Picasso, van Gogh, Serat. One van Gogh nearly brought me to tears - two sunflowers - I was so close I could see the tiny cross-hatch red paint strokes brilliantly picking out the details of the seed head.
Five to one and I headed for the elevator to go meet up in the gift shop. I managed to get off on the wrong floor thanks to a 'helpful' security officer. As the elevator doors closed behind me, I found myself on an administrative floor with all doors closed and locked. I didn't panic, just headed to the stair well to climb up or down to the floor I needed to get out on. That door banged behind me too and now I was locked in the stairwell! Climbing up or down didn't help. All doors were locked. All was quiet and knowing it was the weekend, I wondered if anyone would be using the stairs. I still wasn't sensible enough to be worried, rather just annoyed that I had to walk and climb more when my feet screamed at every step.
Finally, I rounded a corner and spotted an older-looking, dusty phone on the wall. I picked up the receiver and dialed 0 not really expecting an answer. Surprisingly, an operator answered and after my breathless description of my predicament, reassured me that someone would come find me. After she disconnected, I waited a long time in silence before finally, a voice on the other side of the door tentatively called out, "Hello?" I called out too and a lovely man working overtime in one of the offices rescued me, saying he found my location using the videos in the security office. He then escorted me down winding hallways to the elevator, used his key fob to get it going and emphasized that I should get off on the FIRST floor! He also told me that I wouldn't have spent the night in the stairs - at closing time, alarms are triggered, especially in the stairwells, and the minute I moved an inch all sorts of interesting events would have followed....
A lesson. Never, never follow me if you aren't sure of the directions. I never really know where I am.