Separated from his mother, the baby monkey huddles in the corner of the cage. It almost seems as if he is pleading with the scientists studying his behaviour, who are visibly moved by his distress.

We, too, are social mammals, and — just like the baby monkey — we are deeply affected by being separated from our loved ones. So much so, it can feel worse than physical pain.

But separation is part of life, whether it’s a major event — death or divorce — or a lesser one, such as leaving a job, parting from friends or sending our children back to school. Sadly, no one teaches us how to say goodbye. 

Some people cover their natural awkwardness by saying they can’t bear it: ‘I won’t come and see you off, I can’t stand goodbyes.’ Others cover up their embarrassment with gruff heartiness: ‘So, let’s not get soppy. Cheerio then!’ Other people — probably the bravest — just burst into tears, without thinking.

In The Little Prince, the fox and the boy become friends. The wheat fields take on new meaning for the fox as their colour reminds him of his friend’s golden curls. Saint-Exupéry describes their parting: ‘And so the little prince tamed the fox. And when the hour of his departure drew near, “Ah,” said the fox, “I shall cry.” “It is your own fault,” said the little prince. “I never wished you any sort of harm, but you wanted me to tame you.” “Yes, that is so,”  said the fox. “But now you are  going to cry!” said the little prince. “Yes, that is so,”  said the fox. “Then it has done you no good!” “It has done me good,” said the fox, “because of the colour of the wheat fields.”’

The saddest thing of all would be not to feel sad when leaving someone we love. That would mean our shared experience was of no significance. That is why, as the fox shows us, there are wonderful ways to say goodbye. We can express our sadness at the parting, and tell the other person what we keep of them in our hearts. This will ensure that the bond between us endures.

As she says goodbye to her young son before handing him over to his father for a month, Tamara, 39, reminds him that the love they have for each other will make them feel better inside: ‘You know we’ll feel a little sad when we’re not together, so when you’re missing me, just imagine what I would say if I was there to comfort you,’ she said. ‘You’d say, “I love you.”’ ‘Yes, I would. You see, I’ll be with you all the time in your head, and you’ll be in mine.’

In her own way, Tamara is using a technique practised by Milton H Erickson, the inventor of modern hypnosis. Preparing a patient who was worried about leaving his care to carry on his life without him, Erickson reassured him, ‘Remember, my voice will always be with you.’