Communications Minister Malcolm Turnbull's legislation for a mandatory data retention scheme - which would allow companies to store customer records for two years - could be a boon for us all. Seriously.

Don't remember when you last visited the dentist? Your mobile phone metadata will tell you. Suspect a charge on your credit card statement is a business expense, but have no diary entry for that day? Metadata will detail your movements that day, and jog your memory. Forgot the dates of that fabulous holiday? Easy. Suspect you really are not going to the gym as much as you'd like to believe? Metadata doesn't lie.

Using metadata to track your own everyday movements could bring countless health and lifestyle benefits. Credit:Glenn Hunt

And that's just location data from your mobile phone. Match this with your Google searches and your purchases at the supermarket, and you have the kind of data richness that can predict your behaviour, and alert you to potential issues you didn't even know were coming: like depression, diabetes – even pregnancy.

Based on your purchases alone, Target (in the US at least) can predict – with an 87 percent accuracy – if you're pregnant six months before you're due. It matches your buying habits with your credit card, laybys, use of coupons, surveys completed, refund requests, calls to the customer help line, or if you've opened an e-mail they sent you.