"I never felt true love until I was with you, And I never felt true sadness until you left me."

As a phrase-
a novices beginning
an experts puzzle
As a relation-
a youngsters pride
every elders asset
As per history-
the sole relation which has
umpteenth examples justifying
its presence in numerous books
As per knowledge-
it is a storehouse of
immense knowledge which
is imparted through surplus examples
Its the bond of trust i.e FRIENDSHIP

-Uday.G