For the first time since I started to take an interest in such things, an internal motivational memo has been doing the rounds online not because it is deemed bad, but because it is deemed good.

It was written by Joseph Mauro, head of fixed income at Goldman Sachs in London, and sent to the bank's demoralised young associates in an attempt to stop them quitting to join internet start-ups. "Every young person in finance should read it," gushed the headline on Business Insider, which reproduced the email last week. I turned to the email and found that superficially, at least, it had a couple of things going for it. "Based on the number of you reaching out to get on my calendar or grab a coffee . . . there is clearly angst across the floor," it began.

Mr Mauro has evidently mastered the first lesson in how to communicate with young reports: when morale is bad, say so. The only shame is how he puts it – the “reaching out” and the “grabbing” a coffee are at odds in their cheesy jauntiness with the reality of a career discussion with a Goldman partner.

Mr Mauro then promises to desist from offering advice: “I know you will discount my opinions as biased and out of touch.”

He’s right there – they will. Until he later screws up by offering opinions anyway it seems he has also learnt lesson two: youthful charges tend not to believe or agree with a word you say.

Stupidity of timing

Instead, he chronicles the wrong turns he took in his own career, and repeats the duff advice he was given along the way. In 2000, he quit Goldman after only a year to join a start-up just as the internet bubble burst. The stupidity of the timing (along with the suggestion that leaving Goldman now for a start-up would be equally dumb) he neatly illustrates with a series of charts.

This shows he has learnt lesson number three: young people have had it with words. An email composed largely of Bloomberg screen shots (or pictures or video clips) has a much greater chance of being absorbed than frumpy old paragraphs of text.

He then repeats the advice given by a trader who said Fulham football club season tickets were a better bet than Chelsea, and Citi a better bet than Goldman. “He is now in sales,” Mr Mauro gleefully reports. Here is lesson four: to get your audience on your side, try laughing at a stupid third party. This is a low trick but it always works – I know because I’ve built a career on it.

In his life so far, the only advice Mr Mauro has heeded came from the founder of the internet start-up who told him in 2000: “This business is a marathon. You are back at the beginning. Start running.”

In turn, this is the advice that he is now passing on to his associates: “Keep running.” He ends the email: “This will give you some context . . . when every so often . . . you get a one-liner from me that simply asks “What mile are you on?”

Reading this, I asked myself a related question: what planet is he on? The answer must be that he’s on planet Goldman, where all the metaphors are male and sporty and about endurance. And where, despite the assertion that there will be nothing handed down from on high, there is facile advice, offered with the fond expectation that it will be followed.

Baffled banker

If I were a young Goldman banker I’d be both unmoved and baffled by the edict to keep running. At what speed ought I to run? In what direction? Is it OK to rest sometimes and have some water? How long must I go on? Why do I need to run a marathon anyway?

I dare say what Mr Mauro was trying to say was that it’s a long game. Markets go up – and down. Morale goes up – and down. Bubbles inflate – and burst. Things that affect a decision now don’t endure.

It’s all true. And it is the same thing I sometimes say to my children as they start on their careers – but they don’t take any notice. Not because I’ve failed to pepper the message with Bloomberg screen shots, but because if you are in your 20s there are no obvious benefits to playing a long game – and lots from playing a shorter one. A satisfying career, to extend the tiresome metaphor, is less a marathon than a series of sprints.

Yet this isn’t the main reason Mr Mauro’s memo is hopeless. Its biggest problem is that it fails to heed the most important lesson of all. This states that there is an inverse relationship between how many people an email is addressed to and its power to motivate. When aimed at a mass audience, the power of a memo will always be zero.

My advice to the Goldman boss goes like this. Forget emails. Reach out individually to any associates you want to keep and grab a coffee. Tell them they are brilliant. Offer them more money. Then you will get them to keep running – but only for so long as it suits them to do so.

Copyright The Financial Times Limited 2016