This song is created by a chinese music band called 逃跑计划, released in their 2011 album 世界. If you ever miss someone who was once dear to you, i recommend you to sing this song till you shed tears.
According to the song wiki page, the song's inspiration came from the songwriter missing his ex-girlfriend and his past friendships. He was asking himself that even though those memorable relationships were all in the past, even though there were lies along the way, even though both parties had never keep in touch for a long time, if both parties are given a chance to interact with each other near their dying days, will they agree to it.
The song catches the hearts of many easily because the lyrics itself is so relevant in real life, the song arrangement is easily digest and be remembered. The chords progression of Em-C-G-D in all the chorus gives the song a very powerful emotional built-up and release. I started with plucking, all the way until the end of second chorus then i start strumming to pick up the intensity, until start of outro, i pluck to give it a silent end.