I was reminded, yesterday, of an old rule of mine; “don't do important things when you're feeling sick or tired”.

My rule dates back to some time in my mid-teens when I spent an evening soldering up a kit for what was then known as a VDU (in this case a single board that acted as the display part of a dumb terminal). Unfortunately I was already tired and excited (I'd been waiting for this thing for a couple of months). After a couple of hours of work, and having already soldered in about half of the 40 or so 14 and 16 pin I.C.s, I realized that I'd put them all in backwards! Needless to say I spent the next few days de-soldering–a much more tedious process.