Oh, Hi, Dad
Try to recall at least one face that you see on the bus or train every morning during your daily commute. It’s pretty hard to place faces on people that you don’t know or care about. You’ve probably seen hundreds, if not thousands, of different faces on the train at one point, and the chances of finding the one face you were looking for is astronomically low.
This guy was paying his father a visit in NY, so he hopped into one of the cars. The train was chock full of sweaty, exhausted people, but as the OP looked down, he realized his dad was seated right in front of him. Out of all the trains, all the departure schedules, all the people he came across, he found his dad.