So to put it another way, saying Mombasa was part of Zanzibar in 1961 is like saying Hong Kong was part of China in 1961.
Yeah, pretty much. Sort of like the English flag was raised on Hong Kong island in 1841 but the treaty wasn’t signed until the following year. Or like my grandmother was born and raised in the same house but borders changed several times so it might seem like her family was constantly moving. These things take time. The arguments that Kenya wasn’t a country when Hussein was born don’t hold water.