Sunday.

It is a discipline. Being cheerful. An act of the will, sometimes.

You know what it’s like when something has upset you long ago. An apparently innocent trigger can have a significance far beyond itself.

For a long time setting foot inside a church could produce in me the most absurd, disproportionate, debilitating weeping and panic attacks, sometimes lasting all day. Exposure – incidentally, the classic treatment for OCD – seems to have desensitised me enough that I was able to attend Serena’s baby’s baptism last spring without embarrassing anybody. And, far more important to Serena herself, enjoy it.

After Bink came out of the Florence Nightingale Unit, she shaved off all her hair. That is how I still see her: as a convict; as one who must do penance; as someone new-released from a concentration camp.

But it grew again, and when in 2012 Serena asked Bink to be her bridesmaid she also asked if she would mind, please, not cutting her hair. So that when she invited us to her degree ceremony the following summer, just before the wedding, I saw a stunning young women, all her life glittering before her and golden hair flowing down her back, step up to shake the Vice Chancellor by the hand... and with a shock of astonished joy realised it must be Bink.

In the dim and dismal dark autumn which followed, when we found her at dawn in a hospital in Staines after worrying for her life all the night long, her hair had been chopped off with kitchen scissors.

Eventually the years delivered her home again, battered and broken, and we began on the long process of trying to help her heal. Again. A couple of years ago I arranged a shampoo for her after she hadn’t be able to touch her hair for months, but she came home so humiliated by their kind and patient attempt to untangle it hour after hour that she used the kitchen scissors again.

And cut the heart out of me along with her lovely hair. For a while I believed I could not pray, or hope, or even care any more. But being a mother is not voluntary and nor is love.

A few nights ago she told me her mind was so broken, those years ago around the time of Serena’s wedding and her graduation, that she can’t see how even the Priory can mend it any more.

Then on Thursday evening I glanced through the kitchen window and saw her, her hair a quarter of an inch all over again. Just as when she was seventeen.

Yesterday we were in the city of my childhood, the city where Bink graduated and Serena married, and just as on the night before Serena’s wedding, the sun was slanting on the punt poles.

There are good memories as well as bad, and you can choose which to call on.

Hair grows. Minds mend. Bink has a lovely, pretty head and perhaps has shaved away some of her pain.

It is a discipline, being cheerful. And today is a fresh beginning.