This is a really good point. It reminds me of friends or family members who were unemployed, yet they refused to apply for jobs outside the field they wanted to be in or what they were previously in, thus perpetuating their unemployed status beyond what it had to be.

I think it does stem from an insecurity as you say: fear of trying and failing, not really thinking they can succeed at something new. We like what we know, I guess.

Personally, I like learning new things. Not random stuff, but often a new interest will come into my view and I'll do what I can to learn it for my purposes. The thought of impressing people with what I know never enters my mind.