Yeah, anything you carry all the time becomes an object of carelessness eventually. Just human nature.
How often have you lost or dropped your wallet, keys, cell phone, sunglasses, ect. ?
And even if YOU never do, rest assured that MOST people do.
If you are forgetting that you have it then IMO you aren't gonna need it, and if/when you do you won't be able to think clearly enough to use it to anyone's benefit.
You're better off keeping yourself physically fit, and trading your flip-flops for a good pair of running shoes.