I write code as part of my job but also tend to have a lot of pet projects I think about in my spare time. A lot of those projects are not specifically targeted at solving an actual real problem but are just a curiosity (like my Duktape/ECMAScript thing that could import and call DLL routines.) I often find it difficult to choose which one to continue working on and end up not working on any of them because I can't decide which one is more interesting at the time! Or I get stuck and struggle to find a way around whatever roadblock I've hit.