The good thing about life in Brighton is that it's full of surprises. One moment you're standing quietly at a bus stop; the next you're being head-butted by a total stranger. Just ask Lisa's Mum. She certainly didn't see that coming. Although she does have glaucoma.

We had a phone call on Monday night from the aforementioned mother-in-law to say that her journey home from here hadn't gone quite according to plan. She'd spent the morning with Amelie, so you'd think she'd be used to physical violence, but after lunch she headed off to collect her grandsons from school. Having waited at the bus stop for a few minutes, two buses arrived together (obviously), and she made for the second.

Unfortunately, a younger woman decided to run for the first, and in her enthusiasm for public transport (this is Brighton after all), she somehow collided with Lisa's Mum. The exact details are sketchy because, let's face it, it's not easy to remember stuff when you're unconscious, but apparently the woman nutted my mother-in-law in the face, and she went down like a sack of potatoes.

There's no suggestion that the act was deliberate (although personally I'll do anything to beat a pensioner to the disabled seats), but the result was that she hit the deck, hurt her arm, and passed out for a moment. As luck would have it, this all happened directly opposite the hospital. Unfortunately my mother-in-law's the kind of woman who won't venture inside unless she's (a) strapped to a stretcher, or (b) buying chocolate from the hospital shop. So instead of seeking medical attention, she took a deep breath of exhaust fumes and crawled straight onto the bus.

By yesterday however, she'd realised the gravity of the situation. That's the same gravity that pulled her down to the pavement. She still wouldn't see a doctor, but she let Lisa nurse her at home for a day. So having seen twenty-nine patients of my own in Horsham, I made Lisa's Mum my thirtieth, and headed straight over there after work to gawp at her injuries.

To be honest, I was quite shocked by what I saw. The woman looks like a cross between Mike Tyson and a panda. She's got a nasty black eye and a bruised arm, the like of which I haven't seen since I physically assaulted Amelie in Lidl. I think she's got post-traumatic stress disorder too. Although she still insisted on making me a cup of tea.

So Lisa and I spent the evening at Asda, doing her shopping, and wondering if we could teach her to use a mobile phone. We decided we could. Just as soon as hell freezes over. In the meantime, we delivered her shopping, made sure she was ok, and returned home to discuss how we might be able to persuade her to slow down and take things a bit easier.

We were interrupted by a phone call. It was Lisa's Mum, calling to say she'd decided to go shopping at Marks & Spencers first thing this morning. There's just no telling the woman.