This kind of thinking is why most of my "side" projects aren't on Github. Sometimes a new algorithm or technology I hear about peaks my interest, and I spend a few hours playing with it. But in the end, I don't have something I would be proud to show or that properly showcases my skills, and so I don't want people extrapolating from that.

Then again, I don't claim to be an expert in these skills, and don't put them on my resume, which seems to be more what you are referring to.