The first Tuesday of every month is free at the San Francisco Museum of Modern Art. I was lucky to be there on that day, courtesy of my most excellent and cost-conscious aunt. She, my mother and I went there right after I picked up my five-year, multiple-entry visa for Ukraine. But that's another story, a story with a happy ending (so far).I am not a big fan of museums. My problem with them is that there's too much information to take in. I want to dive deep, but it's usually impossible, especially if you have kids with you. Worse, I quickly develop museum back, a medical condition in which your lower back starts to hurt badly in museums. I don't understand the mechanics, but I feel back pain within 15 minutes in a museum, although I can walk for hours on a hike. Definitely an area under-explored by science. But this museum didn't cause me too much grief, even though most of it was incomprehensible. There were paintings of graph paper, which apparently deeply moved a wealthy couple named Fisher who collected much of the art. Some paintings consisted of a single color, or messes that my own children could make within an hour. But some of it was elegant, work that could never be done by a child, or by even by me. I was happy to see originals of famous artists like Mark Rothko and Andy Warhol. It was interesting to read about the various phases of modern art, and to see how it was expressed. But my aching back had more power over me than my mind. It wasn't long before I was anxious to leave, masterpieces notwithstanding. My mother and aunt were on the same wavelength, so we went to the gift shop. Here I found a present for my wife: earrings made by a local artist. A major shopping triumph and a big burden off my back. It would be useful, I think, and educational, if there were shopping malls that consisted of nothing but gift shops from art museums around the world.