‘Have a good day, Olive: seize the day! And thank you so much for helping me earlier,’ she says, jiggling her bad arm at me. ‘I hate to think what might … well, thanks for helping me.’

Our conversation from earlier replays in my head, her voice ringing in my ears: No choice is the wrong choice, because it’s the one you make at the time with the information you have.

‘It was lovely to chat to you. And remember to use your stick. Bye, and see you soon!’ I find myself giving her a big hug as I leave.

Turns out it’s the kind of day where it really does matter if you leave the house and forget to wear deodorant. It’s four in the afternoon and my iPhone tells me it’s still 22 degrees. It’s like ‘yay shorts weather’ slash ‘oh shit global warming’. The shade of London’s parks looks like an old faded sepia Polaroid, like those stained photos that have been passed down in an old dusty jewellery box from grandparent to grandparent. The parks are brown, dry and crispy already, and it’s not even May yet. I’m scared of it getting any hotter. I don’t feel quite myself if I’m not wearing big baggy jumpers and woollen beanie hats.

I get the tube to Green Park station; it is pretty disgusting in this heat and results in droplets of sweat dripping down the backs of my thighs and into my socks. I hope no one notices. I’ll assume everyone is too busy worrying about their own sweaty crevices.

Isla and I have decided to meet for an afternoon picnic in Green Park, in a nice patchy bit of grass near Buckingham Palace. We decided earlier this year to do more ‘London things’ together. But this sunny, La-La-Land weather is bringing far too much pressure to be sociable. I know I’ve been too busy moping around of late, hiding away from the world in my flat, but I sense Isla really needs some support. She’d been ignoring all of our calls, while continuously posting some old photos with long waffly captions to Instagram, which is really unlike her.

I meet Isla by the Tube and we go to the M&S food shop. We buy a soft French baguette, some cheese, some olives, a bottle of wine and some alcohol-free beer for Isla. We scan the park and find a spot with some dappled shade under a tree. A group of young boys are kicking around a football, two teenage goths are on a date and they sit flirting and flipping through a magazine about tattoos and piercings. We sit near a young hot dad and his toddler daughter who are reading a David Walliams book together. He is doing different voices for the characters and she’s laughing along encouragingly. It’s very sweet.

Isla and I like doing nothing together. We mainly just lie in silence, or read books in restaurants together, and if we’re outdoors we will listen in to everyone else’s conversations around us and one of us will occasionally pipe up with a deep, existential question for us to interrogate. One of our favourite games to play is coming up with someone’s whole life story based entirely on their style and choice of shoes: Clarks shoes = accountant with a mistress; Russell & Bromley boots = stay-at-home mum running a secret illegal business; Stella McCartney flatforms = retired artist who once shagged Mick Jagger; metallic Converse trainers = tattoo artist or body-piercer who used to be a policeman. You can tell a lot about a person from their choice of footwear. Sometimes we would elaborate wildly on these stories, as it would distract Isla from her pain, even if it was only for a few minutes.