The yellow Raincoat fades at the station

"I was at this sprawling, brightly lit train station that looked like an airport terminal. I was holding my son's hand, except he was maybe four or five years old again, wearing that bright yellow raincoat he used to wear every day. We were waiting for a train that I knew we had to catch to get home, but every time one pulled up, the sign on the front would change to a city I’d never heard of. I felt this crushing, heavy ache in my chest because I knew time was running out, though I didn't know for what. I turned around to grab his juice box out of my bag, and when I looked back, he was suddenly a teenager, standing across the tracks on the opposite platform. He wasn't upset, he was just waving at me calmly while this rush of commuters moved between us. I tried to call his name, but the noise of the announcer kept drowning me out, and I just stood there watching his yellow coat fade into the crowd while the train finally pulled in."