reminds me of the situationist "sous les pavés, la plage!" or "under the pavement, the beach!" ...

You're quite right. Just paraphrasing one of my favourite slogans from that mythological(?) May 1968. Just being a Groucho Marxist (to reclaim another saying of the time).

but of course, that doesn't account for what's going on under the tarmac, in your mind ;) what *is* going on there?

That's a good question indeed!