Standing on the train the other day, I saw a young businessman, white earphones in his ears, reading or watching something on his phone. It was either a long read or a short video, because I didn’t see much hand movement indicating scrolling of content on the screen. He didn’t have quite a stern look, or didn’t look serious, but his face was fairly nonchalant. I wasn’t observing him specifically, but it was impossible not to notice the smile that quickly emerged on his face.

It was almost a grin, but he didn’t grin wide enough to show teeth. He seemed to laugh gently, before his face returned to the state I initially saw it in, but with a subtle afterglow.

I know I do the same. I had no idea what this young man was reading or watching. I had no idea what he was feeling. But it was that sudden smile that radiated across his face that made me feel warm and fuzzy inside. Several times, I’ve caught myself suddenly laughing, or simply grinning, at something I have read on my phone, or in a book. A fiction novel might not give so much away, because it’s a medium that encourages your imagination to work a little bit more. Nonetheless, the valuable experience one has with a book can be highlighted by their finger tracing over the paragraphs of the page as they read, suddenly flipping pages as they read a bit faster, probably aiming to reach the end of the chapter just before the train reaches their stop.

On a phone, something as simple as a text message from a loved one can make someone smile. Had they been having a bad morning, or a bad day, just a message would cheer them up. You can see someone smile at a message on their phone without even knowing the content of the message.

It doesn’t matter what it is, but seeing the transition from concentrating, being content, or neutral, to completely smiling, watching someone’s shoulders relax, their eyes light up — is witnessing someone’s day being made, and you don’t get to see that every day.