Even though I do get a satisfaction close to physical, seeing a clever Object-Oriented design, it never stops to amaze me that, as OO purists are ready to cut each-others throats over certain design decisions, the most important and sophisticated piece of software we use - operating systems - are almost entirely written in a non-OO language like C and some of it - even in Assembler, for that matter. This is quite ironic but shows the most important point that is, unfortunately, often forgotten - it's not the "best practice" techniques or "design patterns" that matter!