I have the impression that Singapore doesn't really exists as an entity in itself, that is more of an invention, a fiction made of money and colonialism, but a sort of fiction nonetheless. I'm not discarding the hard facts about the river and the traders, and the chinese, the malay and the english history (even the japanese), but there's something like a fictional narrative going on about the place. All places have one, that's true, but maybe it's the fact that 30 years might not be enough time to settle down that fiction.
And funnily enough it's for fictional reasons that I mostly remember the city: I remember seeing the second movie of The Hobbit, I remember inventing some amazing story about how the Cloud Forest of Gardens by the Bay was actually an experimental ship ready to launch to space with specimens from a few of the different habitats of the world, and I remember Books Actually and reading, reading, making up tons of stories in my head, like it was about to burst. I guess that's why I tend to forget I was actually there.
Dreamlike and fictional, not really 'there' or 'here' in the same sense (or intensity) that the rest of places in Asia felt like. My own little rabbit hole, but on a direct line to my head.