Since I started tinkering with it in about 1997, I've been trying learn new stuff every chance I get. With the continuous flood of new goodies pouring into CPAN, I'm always learning new stuff. I also learn when I get a chance to go to http://yapcna.org -- last year's event at Madison, WI was another terrific opportunity to learn the latest cool stuff.
Perl 6 is being refined and updated as I write, so there's that to stay up to date on, though I don't have time myself to install it and tinker with it.
I replied 'hundreds' of hours, but it's probably more like 'thousands'.
Alex / talexb / Toronto
"Groklaw is the open-source mentality applied to legal research" ~ Linus Torvalds