I think you've been very lucky.
I'm 64 and still working freelance, nearly every day I get emails that are orthogonal to my skill set. For example, I've never been a tester and it's not on [and never has been] my cv, but I get emails for testing jobs.
That's apart from the over-specified buzzword bingo related to web CMSs and frameworks. For example, someone that's pretty good with Drupal [not me] can probably deal with Joomla after a week or two.
My main niche is Perl but I did an MSc project in Java, so I can read it and do elementary maintenance programming. But sometimes I see Java/Perl/Ruby/C#/bash specified in the same ad, makes you -really- wonder about the architectural choices going on in that shop, doesn't it?
To be honest, with honourable exceptions [you know who you are] most of the ones I've met seemed to have started their lives as estate agents [that's real estate brokers in the US] or car salespeople.