Leftwing Idiot helped me down the stairs from his flat yesterday morning. To do this, my right arm goes under his and round his middle and he puts his left arm round my middle.

As we came down the stairs I was holding onto the banister with my left hand, while my right hand, round Leftwing Idiot, went on ticcing.

Usually it’s my own chest that I bang, hundreds of times a day, but because of the position of my arm, my fist kept punching his instead.

Each time I hit him he said ‘Ouch!’

When we got to the bottom of the stairs he looked relieved and said, ‘Is that how hard you hit yourself? It’s really hard!’

I do punch myself quite hard but because I’ve been doing it for years my chest’s toughened up so it’s not particularly painful any more.

Sometimes people may assume I’m fragile or weak when they see me using a wheelchair or needing help with everyday tasks. In fact, because of the way my tics keep me constantly moving, the opposite is true and really I’m super strong. This is particularly true of the muscles used in my most regular and repetitive tics.

I’m obviously glad to have healthy, strong muscles. But I’d prefer not to feel my own strength hundreds of times a day. Leftwing Idiot takes a similar view now!