As the Guardian's John Crace discovered earlier this week, even David Hare, Julian Barnes and John Eliot Gardiner are sometimes bored during live performances. I've written before about how boredom can be an essential part of the theatregoing experience. And not always in a bad way: a spell of boredom can often be the precursor to a breakthrough in understanding and appreciating a work of art.

But some shows are not just boring, they feel intolerable. When my eldest daughter was little and I took her to the theatre, I always made it clear from the outset that, because the trip was work for me, if she hated the show, she would just have to suffer in silence. She always sat quietly, but the harrowed anguish on her face was a sight to behold, making Edvard Munch's The Scream look, if anything, restful. In fact, in most cases her honest response to what she was watching was spot-on.

Why is it that bad productions in the theatre are so painful to watch? A boring book can simply be abandoned and you can walk away from an installation or painting in a gallery if it really hurts to look. I've sat through some appalling movies without experiencing too much distress, but an awful theatre show sometimes feels physically painful to endure. The other week, a friend remarked about a show: "After the first half-hour, it felt like someone was sticking needles in my arms and legs."

I suspect it's because theatre is live, so it feels rude to leave. But the same is true of a classical concert, and yet it feels easier to endure a concert you're not really enjoying – you can just let your mind drift. During a theatre show, the mix of aural and visual stimuli means that your attention is constantly being reclaimed, even when you don't want it to be.

But then, some kinds of bad theatre production are more intolerable than others. I'd prefer to be stuck in a terrible promenade performance for four hours than stuck in my seat in front of a mind-numbingly tedious play for three, simply because the physical freedom of being able to move about brings some relief. A mediocre musical, or terrible pantomime is far more trying to endure than a straight play. Maybe it's because, at the former two, you know you are supposed to be having a really good time, and the harder and more desperately the cast work, the more it exposes the gap between expectation and reality.

So if you've got any theories why theatre might take the crown as the art form that's hardest to endure, do please tell us – and if you haven't wiped them from your memory, share your most painful theatre moments. We'll try to apply some healing balm.