We all get lumbered with mythologies about our character long after we’ve outgrown them. In my family, for instance, I’m thought to be fiercely competitive, keen only to do those things at which I excel.

This version of me came about with good reason: at about ten years old, I asked my mum whether I stood a chance of getting into Oxford or Cambridge; in my teens, I could hardly enjoy exam success if a classmate got 98% when I got only 96; I was so appalled at my ineptitude at driving that once, during a lesson with my dad, I stormed out of the car at traffic lights, leaving him to take the wheel. My parents were amused and bemused by the precocity and ferocity of my ambitions, wondering how I’d acquired such traits.

Friends I first met in my twenties, such as Emily, rarely recognise my family’s characterisation of me. In my own narrative, my competitive streak disappeared during my university years. At Cambridge, I tell myself, I learnt to study simply for the joy of it; I became privileged enough to consider reading and writing and thinking as ends in themselves.

But when Emily commissioned me to write about gymnastics, the memories I mulled over complicated my own version of this change in me.

After years of pestering my parents, they let me join a gym club when I turned seven. Even at that young age, I was acutely aware of the need to catch up with those who’d been training since they were three: I’d get really worked up about competitions, not allowing my parents to watch, and eventually feeling devastated when an excruciating 3.0 on the asymmetric bars led to my demotion from the squad.

But I carried on training throughout my teens, attending as many as five sessions per week, long after I’d accepted that I’d never get back into the first team, let alone really make it as a gymnast.

The experience of practising something that didn’t come naturally gave me a tiny glimpse into my sister’s life. Lou’s cerebral palsy and autism make everyday tasks at least ten times harder for her than they are for me. After years of hearing me talk nineteen to the dozen, she kept on sounding out words in front of the mirror until she eventually said them clearly enough for us to comprehend; after years of watching me cartwheel around the garden, she managed her first steps at six.

More remarkable still, Lou undertakes her daily graft with such aplomb that it rarely comes across as onerous. She’ll introduce herself to strangers, trying out her favourite phrases, and she’s invariably the first one on the dance floor and the last one off. Lou’s zest for life is never based on achievement or competition, her sense of self-worth never reliant on beating someone else.

When I made the choice to continue with gymnastics, I came to value the journey without getting fixated on the destination – a lesson that’s served me well when it comes to writing. It strikes me now that I was unwittingly following Lou’s example by doing something simply for the love of it: a quality that comes naturally to her but that was at least ten times harder for me.