My first solo was earlier in the year, after 3 circuits and taxi back my instructor told me to wait before we got back to the parking. He radio'd (?) to say there was a change of detail for one circuit. Told me to do one with a full stop on my own. I barely had time to think about what was going on. Out he hopped and off I went.
I had exactly the same thought downwind as a previous poster, "Christ, I'm flying!"... The landing was ok, if a bit firm (even now my landings tend to be firm, a niggle I need to iron out) and the smile lasted for about a week! Finished my PPL the beginning of August.