I eventually started thinking of side projects as the software equivalent of "practicing my chops" as a musician. It doesn't actually matter that much whether a

I eventually started thinking of side projects as the software equivalent of "practicing my chops" as a musician. It doesn't actually matter that much whether all those free-time experiments ever become shippable products - and most of them not only don't, but couldn't - so long as the process of working on them helps me stretch my knowledge and keep my skills sharp.