common expression

it's right that the antonym for love is not hate. you can only love a very small handful of people all your life. But it doesn't mean that you hate the majority of people in the world. Still I don't think the opposite of love is apathy which means indifference (am I right in understanding the word apathy?). I think the opposite of love is not "not love".

meaning lock of interest to each other or indifferences.I think it maybe true but im not sure.

Yes, I very much agree with that. Love and hate are not really opposites; they are both active emotions - that is, they both require one to actually do something about them. Sometimes, even, they can exist together for the same object, as one may love a person but hate their actions. The opposite of an active emotion like this is therefore truly 'apathy' and it is better to either love or hate than not to care.