"closeness made sight blurred"

"If I put a book very close to my eyes,I can't read".

So things happened as it does happen in LIFE.

We were so close to each other.
We were in love.
Then our closeness made our sight blurred.
We forgot our blessing of having each other.
We took our closeness for granted.
We forgot our blessing of having each other.

Then we lost each other?
Only then we remembered our blessing of having each other.
Only then our sight got vision.

Why can't we count our blessing while we have?
Why we take our blessing for granted when we have?