I'm calling you out, no way that was your first time, you're skiing to well.
Especially considering you're on skinny skis.
Thats a practiced turn.
I honestly am not sure when my first time in powder was, but the earliest memory I have of skiing powder was also the first day I skied a black run, I must have been about 7, maybe younger. I was skiing with my dad, and we were sticking to the groomed runs with just a couple inches on top because like most dads, he was a bit worried about me.
We somehow took a "wrong" turn and wound up on a black run, and the snow just kept getting deeper and deeper. When it started spilling up onto my chest my dad stopped, turned around, and told me to be very careful and just follow right in his tracks so nothing would happen to me.
I did as I was told, for most of the run at least, because i didn't want to upset my dad, but I kept wanting to just point it straight down the fall line. I didn't let my dad notice me deviating off course every couple turns though. He still thinks I followed his tracks perfectly.