The Lost Skill

I used to be able to do a perfect cartwheel. Today I watched my niece and her best friend tumbling across the garden, and it struck me - that freedom of movement, that casual confidence in your own body, it slips away so gradually you barely notice.
At ten, I could cartwheel the length of the playground. Now I can't remember the last time I tried.
It wasn't just cartwheels. I could skip for hours, climb trees without fear (I was a proper tomboy), do handstands against any available wall. Each of these abilities faded so slowly, like watercolours left in the sun.
Sometimes I wonder if I am letting age get in my way. Maybe attempting a handstand or a cartwheel might show me the skill isn't as lost as I thought. Well, the mind is willing. The body, not so much!
Today's Memoir Prompt: What skill did you once have that you've lost over time?