Playing sports with someone ten years younger than you is not that big a deal. It's not. One can match their game and stamina, and even their speed and all your extra experience comes in handy.
But it's only after the game that you start seeing the difference between the two of you. Yes, one might be in good shape and all that, but it's easy to see how fast these youngsters recover.
I'm not just finding this out today, though. Few years ago I used to regularly go for a yoga class for kids. The kind of kids who can't even stand still for ten seconds. Yes I did all that yoga with them and felt great! But while I hopped onto my cycle to go back home and eat something after the class, these kids just hopped on their cycles to go to the playground to play till their parents dragged them back home with the kids often kicking and screaming. Maybe I could too, but it would just not be the same.
This was quite apparent during my MMA lessons too. But obviously these kids had been training much before I started (hey, it's a valid excuse.) They have this energy, vigour and aggression I remember having in my late teens till much after my mid twenties as well. Unfortunately, I was much older than most of them and had lost my aggressive streak and got nicely beaten up during most of my sparring sessions.
I played badminton for an hour with a girl ten years younger than me today. And although I matched her game and speed, I was reminded of this very feeling.