Why love itself is invisible

Love...so many ways we try to express it,
Showing affection and caring for others,
It shows many times in different ways,
But does anyone know what true love looks like?
Is it really the shape of a heart?
Could it be this warm feeling inside us?
A feeling so tempting it makes us hot?
Some say 'love' is a fragment of our imagination,
Nonexist...just a temporarly feeling,
Many belive it's the main important thing in life,
But how could that be when there's people in the world that has never experiance this?
Let alone hear those three words 'I love you',
People become so greedy that they want to steal it away from others,
None of us has seen love itself,
And ask why it exist for and only us?
What is love one true feeling?
What makes love invisible...?