Be yourself, because you can't be anybody else. And if you're going to go on teaching don't timetable yourself!" Eric Anderson has always remembered the advice given by the head of his former school, Sir Roger Young of George Watson's College, Edinburgh, when he himself became a headmaster at the absurdly early age of 34.
The first part of it, one suspects, he did not need. The second part of it came in handy because he did carry on teaching his beloved English literature throughout nearly all his years as a headmaster, first at Abingdon, then at Shrewsbury, then - for 14 years - at Eton. At some stage, he would try to teach every one of the boys in that 1,250-pupil school.
The reason for not timetabling yourself, he says, is that asking a teacher to step in and cover for you can breed resentment. "Whereas if you ask a member of staff 'Could I relieve you of 3B for three periods this week?' they are only too delighted."
The pupils were probably only too delighted as well. For Dr Anderson is a natural communicator and enthuser, once described as "the one bright light in the bleak Gordonstounfirmament of the Prince of Wales" and, as we all know (and Dr Anderson is rather tired of hearing), the Prime Minister's Favourite Teacher. One disadvantage of becoming headmaster so young, he now says, is that heperhaps did not teach enough.
Still only 62, he left Eton four years ago to be rector of Lincoln College, Oxford and also became, in February this year, chairman of the Heritage Lottery Fund. This brings him to London at least two days a week.
The fund is overwhelmed with six or seven times the number of applications it can fund out of the Pounds 250 million it has to dispense each year. "The experience of being an unpopular headmaster is going to be very valuable, " Dr Anderson says.
But surely he wasn't? "Well, the ability to say 'no' is going to be very valuable," he amends in his deep Edinburgh voice.
The product of a long line of Edinburgh kilt-makers (his brother is the fifth generation to run the family firm, Kinloch Anderson), Dr Anderson attended George Watson's College, the Manchester Grammar of Scotland, rather than Fettes, the "Scottish Eton" where he later taught. He went on to read English literature at St Andrew's, where both he and his future wife Poppy got firsts, before heading south to write a thesis on his belovedWalter Scott at Oxford.
He is widely credited with having made Eton what it is today, broadening its intake from one dominated by the sons of old Etonians to a much more eclectic - and brainier - mix.
But Dr Anderson says much of the credit for the transformation should go to his predecessor, Michael McCrum. Taking over when the school was at a fairly low ebb, it was McCrum who set about changing the admission system to raise standards of entry. Dr Anderson says he simply carried on the good work and introduced one or two innovations of his own, such as the summer schools for potential Oxbridge students from state schools.
"He's not a radical innovator, he's an inspirer of teachers," says a former fellow head of a major public school. "Once you understand that he's fairly shy, he's very approachable - to pupils, parents and teachers alike. He's an elitist, but also a tremendous carer for the chap who can't quite make it."
Having been in charge of a school of 1,250 boys for so long, what does he think can be done about the problem of boys' under-achievement?
"The answer," he says, "is probably single-sex education - or single-sex classes at least", citing the evidence that Eton is probably the best school for modern languages in the country, traditionally a subject where girls are stronger. "If you don't put them in competition with girls, they can achieve. "
He is encouraged by the Government's "rather courageous" line on the teaching of reading, approves of the proposal to give all schools complete control of their budgets ("The greatest schoolmasters are those who are interfered with least" - he quotes the Clarendon Commission's 1864 report) and is pleased that the Government "seems to have thrown overboard the old baggage that independent schools are wrong".
"For the past 30 years, the independent schools have kept standards high, kept the flame burning bright," he says. "A sensible government would use its experience to refresh the entire system." He would like, for instance, to see Saturday schools run by independent schools in every town.
The main problem with raising standards, he concedes, is getting more good people into teaching. Unlike the Government, he says that that has quite a lot to do with pay. "People who go into teaching are not desperate for a lot but they want enough to own a house and bring their children up," Dr Anderson says.
"Before, teachers were at the lower end of a professional stratum that included doctors and lawyers, but not so wildly below the others. That's still the case in Germany or Switzerland or Japan, but not here."
Eric Anderson has never owned a house, not even a holiday cottage in Scotland. "I've lived in a tied house all my life," he says. Doesn't he sometimes long to go back and live in Scotland? While he agrees with Walter Scott that a man goes mad if he doesn't see the heather once a year, he thinks the place to which he eventually retires will depend on where his children are. (He has two: a barrister son anda daughter who taught at a North London prep school beforestopping to raise her two small children.)
The place for which he really seems to feel homesick is Eton. He misses it, he says, and finds less "buzz" at Oxford, despite the pleasures of comradeship with other heads of colleges. And he points out that being a head of college is not like being a headmaster: the latter is a significant figure in young people's lives, the former "an amiable old buffer wandering around the quad to whom the students say hello nicely".
Perhaps there is no simply no job as enjoyable as being head of a golden school.