The fi rst time I stepped off a plane into a dry Beijing night， I was 19 years old， which meant that I had lived away from home only for two years. I barely spoke a word of Chinese and had only a vague idea about what it would mean to live in a new country.
　　In the beginning， I went on adventures in supermarkets， thinking： “What is this place， with hundreds of noodle types but only two brands of oatmeal？” The people dotting the streets outside were just as novel as the foods lining the grocery aisles. Young East African families were followed by vivacious groups of South Asian boys， with Chinese schoolchildren flitted excitedly through the gaps， their school uniforms hanging haphazardly. This was Haidian District， a place where students from around the world came to study in and from China. It was clear that China’s infl uence over and its attractiveness to the outside world was increasing， and I wanted to know why.
　　I started walking through different districts to get a better sense of the city. Sometimes， I would start a Saturday morning near Houhai， a 40-minute subway ride east of Haidian. The lakes were wondrous， with their commercial walkways and over- priced water bottles. From there， I would slowly wonder into the hutongs， the famed snaked alleyways that wind their way from one end of old Beijing to the other. The elderly women， who I later learned were known as damas， or big moms， sat on small stools and fanned themselves outside their doorsteps. Occasionally， small yapping dogs or a young man on a motor scooter would whiz by and scare me out of my idyllic musings. To a newcomer， Beijing seemed like bustling， magnifi cent centers contrasted with calm surroundings and a pace of life seemingly unchanged for decades.
　　However， although not reflected in the steadfast demeanor of damas， Beijing has in fact changed a lot in the past 10 years. In 2008， Beijing hosted the Summer Olympics， an event that kickstarted the construction of more subway lines， a new airport terminal and many high-speed railway routes， among an array of other infrastructure projects. In the decade since， Beijing has continued to transform immeasurably. Of course， I had no idea that the 2016 Beijing I was seeing was just a snapshot， a grain of sand in the city’s fast-paced turnover rate of development. 　　When I returned to Beijing in September 2019， I found that my picture was entirely outdated. On the surface， the relaxed damas still sat on their small chairs， while the hutongs retained their quiet resilience. But the city was different. Bikesharing company Ofo had come and gone. The folks who had previously been grilling lamb meat in little stalls on the streets were now driving for the ride-hailing company Didi. The group of old men who swam in Houhai was only half in number. All of these changes were admittedly small， but collectively， they somehow fundamentally changed the fabric of Beijing. Regardless， Beijing had grown without me， and now I was trying to fi gure out what happened.
　　But of course， this is an unknowable thing. Every day， Beijing sees more than I will in a lifetime. People smarter than I have fallen into the fruitless trap of trying to understand Beijing， but the people who have lived here all their lives only laugh at these attempts. Still， when I first left Beijing， I thought about it constantly.
　　My mind was repeatedly trying to construct what Beijing looked like a month， six months or two years after I left， from video clips， news articles， blog posts and social media. This is what Beijing does to you—it tricks you into believing that because you have wandered its darkest alleyways and been to its grandest palaces， you have a chance of knowing it， of keeping up with it. But you don’t.
　　The most any of us can hope for are occasional glimpses of it on the subway between stations， in a picture from the 1930s hanging in the Tsinghua Art Museum， or sometimes during early mornings in a park. I try to hold on to these glimpses， but inevitably they always vanish too quickly， leaving me unsure as to whether what I saw was real or just a dream.