Today I scored a free lunch in one of my favourite writing places, the newly refurbished Bush Theatre.

‘Just one of those things,’ the bar guy shrugged, bringing me a (cracking) pastrami bagel. ‘Weird morning.’

Free stuff! Free stuff never happens to me. I’m the kind of person who’s always delighted to pay. I say ‘thanks’ at least ten times in any given transaction. (It’s my ambition to know how to say ‘thank-you’ in all the languages of the world. So far I’m at 47).

I’m rubbish at wangling freebies because I never feel like life owes me anything. It’s the total opposite. My life has been one long procession of unlooked-for gifts. Not least the most unlooked-for, most fundamental gift of all: the fact I’m here in the first place.

So many unlooked-for gifts, a long string of bead-bright flukes. Being born in peacetime twenty-first century Britain. To my parents, who not only had the means to look after me, but who are, more importantly, the best of eggs. My farmer’s-wife constitution. My brilliant tribes of family and friends. My remarkable daughter. Gifts given with pure lottery abandon. Not because I’ve deserved them. They aren’t anything to do with merit. They are utter mysteries. No wonder I’m a serial thanker.

So I need all 47 of my words for ‘thank you’ to do honour to the generosity of everyone who’s coughed up for Cancer Research UK, on account of me running the Coventry half marathon. You helped me smash my target. Thank you all so, so much. I can’t tell you how deeply I appreciate every penny.

I ran a half marathon for Cancer Research because the trouble with unlooked-for gifts is that we never know when they will be taken away. When our grip on the hand we love best will fail. When our bodies will mutiny against us. When someone will drive a car onto a pavement. The morning you’ll leave for work, and never come home again.

I ran because sometimes the weight of our unlooked-for gifts is almost more than we can bear. I have needed running, something I once hated, this dark winter. Some days the only thing stitching me together has been the pounding of my trainers on the pavement. The unlooked-for gift gained from running further has been a stronger body. At times, that physical strength has been all that’s carried the rest of me through the day.

This week, us Londoners are holding our dearest ones a little tighter. And we’re reminded of the only thing to do, when the gifts fall from our hands. When the price of our love is exacted, as it always will be, in its loss.

We have to take the chaotic, the uncaring, the senseless, and weave meaning from it. Make it matter. Take a new bright bead and string it on the thread. Watch it gleam there. Another unlooked-for gift.