As you may know, Yahoo! is primarily a PHP shop, but there's a lot of Perl being used for infrastructure, especially for monitoring. Amongst so many talented Perl developers, I opted to use a framework in order to focus on bringing value at a higher level. With Catalyst (which was new for me,) I read up on the framework as best I could (web/IRC/lists) given the other (Yahoo!-specific) technologies I was learning at the time along with the other responsibilities (product management, project management) I was juggling.
While working with Catalyst, I was burned more than once by assumptions and conventions of the framework I had not had time to go in depth on (they say you use 20% of what you learn, but you never know which 20%, do you?) That whole experience reinforced the notion that you will never always know everything you need to know at exactly the moment you need to know it, even if you're an experienced web developer.
One just needs to be open to change and growth.
And a little extra homework...