I had always thought the whole point of having hybrid sockets around here is to accept both American- and European-style plugs, so I would never have thought that Type O is unique to Thailand. Now that I think about it—my Thailand-bought MacBook came with an extension cord for the charging brick that is Type O whereas the otherwise compact head attached to the charging brick is Type A. I remember bringing it with me to Europe thinking that it would work (because round prongs) and being sorely mistaken!

Everyday is a school day!