In one, I was having a cup of tea (told you it was weird), sat at a table with someone I knew, and my brother was hovering around nearby. The atmosphere and the conversation at the table were fine and the whole setting seemed relaxed enough in itself. I remember looking at the table with the various cups and plates on it, it was a table like those used for outside seating at cafes, with a shiny surface which seemed at once plastic and metallic.
We were indeed sat outside, and there was a little bit of a breeze. We seemed quite high up too. The nearby skyscrapers - well it was interesting to be able to look down on to the top of them, though I don't think my brain's dream-engine conjured up any imagery so obvious as a a bunch of execs playing rooftop golf on specially fitted turf or anything like that. No, they were just the tops of skyscrapers.
Hang on - if we could see down onto the tops of skyscrapers, then we were indeed high up - very high up (notice that for a change I haven't used an expletive for an intensifier, I could have easily said "we were very fucking high up" but I didn't). I suddenly became aware that our chairs and table weren't like normal chairs and tables. Their legs were rather long - we were taller than the skyscrapers, but the chairs and table reached right down to ground level.
My movements, which up until this point had been relaxed and, well, normal, were suddenly tense and frozen, I was in a state of rapidly increasing uneasiness - how on earth was I going to get down? Hugely aware of my own precariousness, and utterly vertiginous. And how did we get up here in the first place? I gripped onto the edge of the table for dear life, the same table that up until now I had been casually leaning on and drinking tea from.

Every movement felt like a trial - one wrong move, it seemed...I clung on and contemplated the terrifying prospect of shinning down the chair legs to get to the ground.
At this point, predictably enough, I woke up, and thought thank shitting crikey for that.
Please note the accompanying diagram, which is merely a guide rather than an accurate representation - I didn't draw it when I was asleep either, just in case you were wondering.