Test the amulet to see if it really does anything

Your curiosity grows. Who was that man and why were the police after him? Was this amulet really that special or did the officer just want to catch up to his partner? The officers were long gone by now so you didn't bother trying to catch up to them. You were never an athlete. You wonder how you could test the amulet to see if it actually worked or if you were just going crazy. It would be too awkward trying to make a random stranger do something and have it backfire so you tried to think of subtle ways for you to do things. You could just go up to a homeless person and test it on them. Even if it didn't work they won't be able to do anything. After all they're homeless.

In the end you decide to go to the coffee shop you usually go to before work. You could use a coffee with the day you've had. You go up to the counter and order an espresso, your usual. You recognise the young girl at the counter from the many times you've been here. Once you order you seize the opportunity to test the amulet. "Could I have that for free?" You ask jokingly, hoping she'd play along if it didn't work.

"Well I don't normally do things like this but I'll let you have that espresso for free today." She responds. You can't quite believe what you've heard. The buzzing sensation made itself known again and you look down at the amulet in awe. You marvel at the potential that this could have on your life.