I've heard that said before, and I don't necessarily agree with it. I guess it all depends on your scope of a new technology. I jumped into ASP.NET about 2 years ago and have learned Javascript, a little jQuery, MVC, and NHibernate along the way. I've also learned how to effectively use Telerik products, how to handle/manage IIS, and the basics of CSS. Some would say I have been stuck in the ASP.NET mindset for the past few years because the majority of things I've learned have been directly related. However, I think my experiences with MVC was more learning a design pattern, NHibernate was more learning how to effectively use an ORM w/ repository pattern and DDD, etc.

If I find that my employment options become limited, I know I have several other skills I can fall back on. I'm not tied to .NET or Microsoft, or even development for that matter. I've worked hard to put myself in this position and I don't have much sympathy for others that haven't. Just as I don't have much sympathy to people who went to college for some crazy occupation because they were "following their dream", but are now complaining because the job market sucks and there's no need for their odd career choice. Listen to my cold conservative side come out... :-)

OK, I'll clarify...maybe not every 6 months....but obviously you've been looking at different tools over the years. Learning tools can have secondary benefits, as you just mentioned. So it sounds like you've been managing your career rather well...not bad for someone once described as a "young pup" :) (haha)