So this will come in handy the day you get robbed after forgetting to charge your phone and decide you'd rather carry on with your afternoon rather than go to the police and then back home.

In all seriousness, I forget my wallet more often than someone my age should. Keeping an extra couple of twenties in my car has stopped that from ever once being a problem. I've never felt the need to have a payment option on my phone or smartwatch, let alone implanted in my arm. What happens when you decide to change banks?