In no particular order, I learned...
restrict with objectin DBIx::Class
And of course, I was again reminded that the Perl community is a bunch of lovley and brilliant people, and that YAPC is one of my favourite times of the year.
A big THANK YOU to the orgas, the sponsors, the speakers, the attendees, and to Larry Wall, how started it all!
If I was cog, here are a few more things I'd say during the opening talk, How to get the most out of a YAPC: