Octopus is such an extraordinarily useful system; it may genuinely be the part of day-to-day life in HK that I miss the most.

The cards are stored value, so transactions happen instantly and can be automatically reloaded from a credit card. They also support non-payment-related functions, so you can e.g. register your Octopus as a building access card and not have to carry around a separate token.

This all applies to London Oyster, too.

Really? I only lived in London briefly years ago, but I can’t remember ever coming across Oyster in any non-transit setting. Maybe it’s like Suica in Tokyo? Technically capable of the same stuff but rarely deployed in practice.

Octopus, in contrast, is almost literally everywhere (except most taxis, sadly). You can use it to buy everything from groceries to petrol.

Pretty much all convenience stores accept Suica. It's much closer to Octopus than Oyster.

> Technically capable of the same stuff but rarely deployed in practice.

Exactly. I doubt it's been accepted anywhere since contactless Visa/Mastercard was introduced in the UK about 2007.

Why though? What's wrong with a normal bank card?

Less cards to carry.

Also, technically, Octopus is a very special bank card, as it's regulated by the HKMA and has a deposits license.

> So Metrocard was to some extent dated on arrival.

That's to be expected with US infastructure. Flying to the US always feels like stepping back in time.