Incest and Morris Dancing

There is a story, probably apocryphal, that Sir Thomas Beecham once observed: ‘One should try everything in life, except incest and Morris Dancing.’
 
I have tried Morris Dancing, but not – in so far as I am aware – incest. I have also tried a number of other things with varying degrees of success, and I have described a few of them in these posts and elsewhere on this website.  But there are two ‘things’ that I could (and can) never make any sense of at all – thermodynamics and accountancy.
 
I was reminded of this while reading Jim Al-Khalili’s book Paradox (a Christmas present). I like Al-Khalili; his BBC Radio 4 programme, The Life Scientific, is interesting and informative, and he is one of the better contributors to the programme In Our Time. His book though, is disappointing – to me at any rate – because I do not find his explanations very helpful.
 
However, it was his chapter on Maxwell’s Demon, in which he invokes the Second Law of Thermodynamics, that left me more confused than when I started. You can look up Maxwell’s Demon and the laws of thermodynamics in Wikipedia; the second law says, in essence, that disorder in a closed system always increases. Fine. But how that is then quantified and applied to the real world using a measure of disorder – entropy – has always eluded me. I’m amazed at the insight of the 19th century engineers who developed the theory and applied it to make better steam engines.
 
Similarly accountancy. I once spent two years studying the subject, and came out knowing one single thing: that accountancy uses a double entry system (which was, I believe, invented by the Italians several hundred years ago). A friend once lent me a large well-printed and illustrated book – effectively accountancy for dummies. On page 3 there was a statement that such and such an item was a credit, whereas I could not see that it wasn’t a debit (or it might have been vice-versa) and I crashed.
 
I did hear a vaguely relevant story that might have been circulated by the Monty Python team. A young woman, having been told by her doctor that she has only six months to live, asks him if there is anything that can be done. “You could try marrying an accountant” he says. “Will that make me live longer?” she asks. “No,” replied the doctor, “But that six months will seem like a lifetime…”