Hieracosphinx

I don't remember any of the visual content of this dream (though it was there), only thought and tactile sensations. Actually, I remember white light like a bright overcast morning, but none of the details. Then I remember 'becoming lucid' and beginning to shout 'increase lucidity', 'increase vividness', etc. which seems to work now, and then seeming to get some sort of response from the dream. But I can't remember the sense of 'wow, this is so real' that I take as the litmus test for lucidity. Notably, at some point in the dream I recall trying to strip naked, which suggests I wasn't fully lucid. If I were ever lucid in this dream, even semi-lucid, it would be an encouraging sign because unlike most I have, it happened during the night without ever waking up.

I think there was another dream that involved something about high-speed trains (my oldest dreamsign, going back to 2011 or earlier, is railway tracks).