Want to know who to blame for your pocket-checking addiction? For the increased muscle power in your opposable thumbs? For the blessed curse that is your mobile phone?
Martian Cooper. Back in 1973, Cooper produced the world's first mobile telephone for Motorola - weighing a shoulder-straining 1.1kg and measuring 23cm by 13cm by 4.45cm. It took 10 hours to charge, and offered a scant call time of half an hour. And no, it couldn't take a selfie.
For the better part of 20 years, technology groups raced to make their handsets the smallest, slimmest and lightest they could (thanks in part to a principle called Moore's law) - until things got smart.
Since then, as this marvellous (if slightly simplistic) evolution chart from the Danish 3 Business website neatly illustrates, the race is no longer to make things a slight as possible.
While we doubt things will return to the 1.1kg proportions of Cooper's original model, it's an interesting insight into the shifting uses and functions of mobile phones: once purely for talking, modern builds reflect the new wealth of application options for the humble 'phone'.
Here's hoping that Kyle Bean attempts to modernise his superb Mobile Evolution Russian Doll set to mirror this post-smartphone shift?