Mine was two weeks ago when I turned up for another lesson on the C172 (16 hours total) and the instructor said to go and take it flying, by myself. This was the first solo time without a check from the instructor first. I had done around 1.5 hours of solo previously, but always after letting the instructor out.
While the first solo was memorable, this was my first real experience as PIC with no intervention, real flying, albeit in a circuit
While everything I read about GA worries me, jumping in the cockpit and flying makes you tune out to all the noise.