There is a reason why "that's how it was" is heartwarming.

That's what I found out. It is an emotional song that conveys calm comfort.
The melody is impressive for calmly sorting out a complicated mind.
Every single lyric is realistic, so I relate to it even more.
It is a song that goes really well with listening to it on a quiet night.
It is a hidden gem by DAY6 that makes you feel more at ease the more you listen to it.