I've had many memorable moments in fandom, but for me, JIB 2013, the first time I met Jensen was probably one of the most profound moments I've had. By that time I'd spent four yearsfangirling over the man from afar, and then to meet him in real life, and stand right next to him ... I entered and completed the menopause in the space of five minutes!
As you can see, all I could manage to do was stand there like a total plank and try not to pass out.
As an aside, I was very proud of myself when I actually managed to exchange about three coherent words with him a year later at JIB 2014!