Flying Scholarship in a Cessna.
Took me by surprise. Instructor called the tower to change callsign, saying "first solo" as I was about to shut down after a circuits sortie. The doors of the Fire station opened and men in silver suits clambered aboard one of the fire engines.
Very sprightly take-off in the absence of the QFI, but otherwise didn't think about being alone until I had a bit of time on the downwind leg when his unfamiliarly empty seat looked rather strange.
Made a complete arse of the approach. Too high; too fast and too much power. Struggled manfully to sort it out with 40° flaps, but by 100' I had to admit failure and go around (called "overshooting" in those days).
My 'second' first solo, in the JP, was sweet as a nut. Pure perfection. By then I'd flown 20 or 30 hours solo in the civvie aircraft so the experience of not having a consultant sitting next to me held no fears and I nailed the speed and altitude and glidepath like I knew what I was doing.
My first solo in a JetRanger was illegal as hell, but that was in Iran and the locals simply presumed I was qualified to fly the thing. It was during the Revolution of Flowers when the Shi'ite hit the fan and I flew it like I stole it. Fortunately it's a very easy aircraft to fly and as there was only me and an hour of fuel and a few boxes of documents, the torque and temps weren't a problem. I got what amounted to an MiD from a famous writer for that one.