You don't think four Rolexes would set off the metal detector or be questioned by customs?
Ahh, but I can say that is my watch.
Right now, it is illegal to carry more than $10,000 in gold or money outside the country without properly declaring it. So if you were caught with 3 gold coins in your pocket while flying to London, you would be looking at arrest or fines. Meanwhile, if you were caught with a watch on your wrist that is almost expected.
Re-entering the country, customs is mostly interested in whether you had the watch with you when you left. That is why they try to mail the watch box to you in the mail, and you wear the watch without the box being present when you go through customs.
In a full on fall of Saigon situation, you can bring with you whatever you want. South Vietnamese officials literally stuffed their luggage with gold bars. If you have someone stealing your stuff, they are definitely going to take your watch too. But, if you are in a more or less normal customs situation, you can bring a watch where you cannot bring coins or bars of gold. Coins and bars of gold look shady where as a watch is normally worn.
I wear an Amazfit smartwatch synched to my phone. It monitors heart rate and sleep (although the latter is a bit sketchy on accuracy).
A $20 quartz watch is literally 100 times more accurate than a $20k Rolex. And do not even get me started on how much more features smartwatches have.
I guess that a mechanical watch would do better in an EMP situation, but once we get there I really doubt I would care about the time.
I Schwarzkopf it and wear two watches, an Apple Watch, and whatever jewelry watch I chose for that moment. The jewelry watch is about jewelry, not about anything else. I do check them more for time, but that is also just because I like looking at them.