Is detachment all about not giving damn to peoples/things? Detachment,
  Everything is lust and mirage


What is the real purpose of life/birth? Aren't we suppose to love, care ?
The real purpose of life is to end suffering. Love is merely one method for preventing &amp; ending certain types of suffering. Non-attachment is another method for preventing &amp; ending other types of suffering. 

For example, when a child is born, it is hungry &amp; alone. This suffering of hunger &amp; aloneness is to be ended by parents feeding &amp; comforting the child. 

When the child gets older, it suffers from boredom &amp; restlessness, so it plays with toys &amp; games to end the suffering of boredom &amp; restlessness. 

When the child becomes a teenager, it has the suffering of sexual urges &amp; engages in sexual activity or gets married to end the suffering of sexual urges. 

As an adult, this person has children &amp; suffers when it sees the suffering of its children so the adult practises love &amp; care towards its children to end its suffering &amp; the children's suffering. 

Later, the adult experiences the suffering of loss; such as loss of wealth, loss of status, loss of friends, loss of children, loss of spouse, loss of health, loss of life, etc. 

To end the suffering of loss, the adult can seek more wealth, more children, more status, another spouse, have plastic surgery or believe in reincarnation or going to heaven with Jesus or God. 

Otherwise, to end the suffering of loss or change, like the Buddha, the person can practise non-attachment &amp; not-self, understanding all of the things that change &amp; are lost never actually ever belonged to oneself or were 'oneself' in the 1st place.