Shaver plugs

I just re-discovered - for some reason the fact never sticks in my head - that the shaver plugs we use in the UK are not in fact an international standard. I know our normal plugs are unique, but for some reason I always think the shaver plugs are standardised so you can plug your shaver in anywhere in the world. And you can't.

It doesn't matter, my UK plug adapters can take UK shaver plugs as well as regular UK plugs. But how many times am I going to find this rather dull fact surprising?