Why some people just don't care?

Some people don't care about thier lover
Some people tell lies to lover
Some people just don't care their lover

I tell myself what wrong with the world on Earth
What causes war
Why some young die
Because war are going on

Some peple don't care thier lover
And some of them kill each other
If what happen if we have not many human in Earth
And we don't reproduce
One day we will extinct

I believe this world will not extinct
But why some people ask me
Why some people don't care
If that is the answer
Until you found the love.