From recording everything we buy to analysing everything we eat

Wouldn't it be insanely cool if every purchase we made were recorded for us online? Ok maybe not for those worried about privacy etc. But for people like me who just want info available and searchable all the time it would be amazing.
I could have found the recipt for the items I tried to return at the weekend. I wouldn't have had to argue with the cashier about the store return policy. Any time I need proof of purchase I'd know where to go.
It's about more than that though. I'm into health and fitness so I eant to know the details about the food and drink I buy. If my shopping receipts were stored online then I'd also like the details of the items I bought to be available. Clickable links to things.
Taking this further it might become possible to start finding out about these food right there. What calories, vitamins and minerals does the food contain? What if I could drag and drop these items onto a daily planner then I'd know a lot about what's going into my body. More than I can work out right now infact because calories are relatively easy to track but vitamin and mineral consumption. That's a whole other minefield.
So if it were possible to collate my purchases online in one place it would make it easier for me to analyse and understand my own life. It'd take me minutes rather than hours to analyse it all,
So how could this be possible? Well I think the technology is just about thete it's about implementation and will of those involved. A simple way would be having an aggregator site that a store could just email the receipt to. You give th2em your id and they send it. They could also email it to you and then you send it on. Your email could recognise the mail as a receipt and import it into the aggregator for you.
As I'm writing this I am realising the privacy, technical and other challenges involved. But as with any idea I can also see the amazing potential of having such info available. Particularly as all shops are moving online and all transactions are recorded digitally. Most if not all shops have a basic structure that could provide most of what is needed.
Anyway. Just thought i'd put the idea out there


edit 13:52
this is a first. I literally just published this post and found out that Visa is trialling technology that solves part of this puzzle.