Re: To balance the scales...
@ Diogenes:
Not to mention the equally vital skill of recognising that USB plugs fit nicely inside RJ45 sockets, but won't work there no matter which way up you insert it.
Protip - something I realised the other day: on every device I own, the side of the USB plug with the USB logo embossed or stamped upon it goes upwards. Noticing that has saved me a lot of random fiddling.