Yes. I wear a Garmin Forerunner 255, wear it pretty much 24/7, off only for shower/bath and charging.
It's amusing that you mention it as "doing the math", it's just something that's second nature to me lol. It's not like I need to think 15 - 12 = 3pm, I just know what 15:00 is off bat.Yes in USA we never use the 24hr format. I believe only our military uses it still. AM/PM is easier than doing the math. You know, us lazy Americans. On subject tho, I used to wear watches but being in construction (Electrician), I would always break, or lose them, so I haven't worn a watch in years. I used to wear necklaces also, till one day getting shocked and it left a burn mark on my neck where my gold necklace was, so stopped wearing all jewelry.