Julia Gillard says the pain of losing power - both personally and for Labor - can be overwhelming but the party needs to rediscover itself after grieving.
Breaking her silence of more than two months, Ms Gillard has written an essay on Labor's lessons and future for the Guardian Australia website.
"I sat alone on election night as the results came in," she writes.
"I wanted it that way. I wanted to just let myself be swept up in it."
She says the loss of power is felt physically in moments of distress - something her Labor colleagues must be also feeling.
"We have some grieving to do together," she says.
"But ultimately it has to be grieving for the biggest thing lost, the power to change our nation for the better."
The former prime minister urges her party to learn the lessons from its 1996 loss and make sure it owns its good record in government while also examining which election promises to keep and which to reject.
She says Labor must stand up for its economic record and also policies that are right but may be unpopular, like carbon pricing.
Ms Gillard concedes she was wrong to not contest coalition leader Tony Abbott's labelling of the carbon pricing scheme as a "tax".
"I feared the media would end up playing constant silly word games with me, trying to get me to say the word `tax'," she says.
"But I made the wrong choice and, politically, it hurt me terribly."
Ms Gillard relates the story of an elderly lady asking her during the election whether it was the fault of the lady or the campaign that she can't understand what it's about.
"After a resounding Labor loss, that word fault is now everywhere," she writes.
"But though it is so painful and so hard, now is a time for cool analysis.
"It is a time to carefully plan Labor's future and its next contribution to the nation."