define love.

someone asked me today, what is "love"?
and I replied, "I don't know how to describe it to you."
that someone asked again, "have you ever been in 'love'?"
I replied, "I don't know. there are different kind of love you know..."
that someone asked again, "such as?"
I replied, "well, like family love, siblings love, brotherly sisterly love and love LOVE."
that someone asked, "have you ever love LOVE someone?"
I replied, "I don't know."

this is by far the most interesting question I got for the day.
it got me thinking.
and really, what is love?