What does Andy Lau's lyrics "I don't love you enough" mean?

Lyrics: Xie

Singing: Andy Lau, Kelly Chen

I don't think I love you enough.

I never forget myself.

Not so devoted

So it will be a complete failure.

(Chen) I don't think I love you enough

I forgot how you felt.

There is no way to do it again.

I have to resign myself to fate.

Not on a moonless night.

You can't close your eyes easily.

Because you will appear in the sky or in your heart.

Not in an endless place

You can't get into that crowded crowd.

(Chen) Because loneliness is not lonely.

(Liu) will wake me up

I lost you because I didn't love you enough.

(Chen) I don't think I love you enough

I don't think I love you enough.

(Chen) I have never forgotten myself.

I have never forgotten myself.

(Chen) Not so devoted.

(Liu) devote himself wholeheartedly

(Chen) So it will be a complete failure.

I don't think I love you enough.

(Chen) I don't think I love you enough

(Liu) I forgot how you felt

(Chen) I forgot how you felt.

(Liu) There is no way to do it.

(Chen) Do it again.

I had to resign (together)

Not on a moonless night.

You can't close your eyes easily.

Because you will appear in the sky or in your heart.

Not in an endless place

You can't get into that crowded crowd.

(Chen) Because loneliness is not lonely.

(Liu) will wake me up

(Liu) I lost it

(Chen) I lost it.

I don't love you enough