I once was blind ........but now i see

This was a part of the lyrics from the song Amazing Grace. Was pleasantly surprise to hear this song from the church website's during their last week's service yesterday. Remembering a dear friend likes to sing this song to my ears and i can't 'stand' it. (Wonder how it would be like if i were to hear again?) So i also ended up doing a recording of the song as a gift to this friend. (haha)

I find the lyrics of the song Amazing Grace powerful and meaningful.
"I once was blind .........but now i see" can be used in many context. One not necessary have to be physically blind, it can be emotionally, mentally, ..............in not realising or seeing the truth. Our judgement may have been impaired by certain factors or circumstances.
We often hear our friends saying during an quarrels or arguments, "i am blinded to know or trust you"

How often do you use these words?