If you haven’t scuffled you haven’t lived, and our local scuffle is the best of the best. A scuffle is a sort of off-road bumper cars in 4x4s, and it’s one of the highlights of the summer. Our car, The Scuffle Pig, was on her third outing this year. We thought she’d been dealt a fatal blow in 2011, when a foolish friend encouraged a fellow scuffler to get her out of a dip by ramming her. The back windscreen was smashed, and I had to leap out and strip my then 12-year-old stepson down to his underpants in front of numerous spectators in order to get rid of the glass. He was remarkably good about it, though. Happily the Pig rode again, sporting four new off-road tyres which cost more than she did. The boys were concerned that the heatwave might have resulted in a dry scuffle — any good scuffle needs mud — but there was no need to worry. It never really stops raining on Exmoor.

Less than a week to go until my stint presenting Radio 4’s Woman’s Hour, and I am terrified. This gig is a big deal. If you’re a devotee of the station you can tell what time of day it is from the voice you hear when you turn on the radio. Your body clock is set to the ebb and flow of the different shows (when my eldest was tiny he could always be calmed by the Archers theme tune). We have one Radio 4 addict friend who has a house in the Caribbean, and listens to it there via the internet. Once the jetlag has worn off you find yourself eating breakfast while listening to Martha Kearney on The World at One, which never feels quite right.

The Channel 4 press office have been in touch with my agent; the Sun are doing a piece on celebs getting freebies and money by tweeting about products, and my name has come up. I ring the press office and ask for the journalist’s number. I don’t want anyone handling this for me; if you have nothing to hide, you don’t need a spokesperson. The Sun journo’s number is not immediately forthcoming, so I tap out a few heated tweets reflecting how I feel about being suspected of being ‘on the Twake’. I also ask anyone whose business I have promoted without wanting anything in return to contact the Sun. Eventually I speak to the journalist and he says that the powers that be are not happy about my tweets — a few people took the opportunity to tell the Sun where to get off. ‘You called me a tosser,’ he says in an injured tone. I apologise, but given that he’d sent reams of my tweets to my employer, suggesting that I’d composed them for personal gain, I think he got off lightly.

Up to London for the premiere of the new Richard Curtis film, About Time. The screening is at Somerset House; I’d never been to one of their movie nights, but I’ll certainly go again. About Time is a gem — delicate and finely tuned, but with a powerful message about how to live life to the full. It’s had a remarkably positive effect on me, which I hope lasts a fair while. For someone whose diary is organised at least a year in advance, it was a timely reminder to live in the present.

We spend the weekend going up and down the Atlantic Highway between Devon and Cornwall. When I was a child, we often went to north Cornwall in the summer. It took forever to get there and the highlight of the journey was lunch at the Little Chef outside Honiton. Now I live near Honiton, so the joys of Polzeath are much closer for my children than they were for my siblings and me. They also have wetsuits and boogie boards, which makes time in the Atlantic Ocean much more pleasant. My parents stopped going to north Cornwall when I was 14, after my mother burst into tears one day and declared that looking after someone else’s house and shopping in supermarkets where they didn’t sell avocado pears was not her idea of a holiday.

My radio-presenting stint is over, and I’m alive, I’ve double checked. Heart still beating, head still attached to body. I didn’t bring Radio 4 to its knees. By the time I got to Broadcasting House, following a bugger-up getting my stepsons to Heathrow and my cab accidentally being sent away, all before 7 a.m., I was terrified. Rebecca, the saint-like producer I’d been working with on this special show, sat with me in Jenni Murray’s ‘Woffice’ and discussed the running order and questions I wanted to ask the panel, who were there to discuss the politics of birth. In the event, I was so nervous about balance, not letting down the Woman’s Hour team and not disgracing myself by leaping across the table, grabbing a panel-member by the scruff of the neck and accusing her of misleading an entire generation of new mothers, that the show was far milder than I meant it to be. But I’m not going anywhere, and those who seek to pretend that anyone can have a transcendental birth experience with nothing more to aid them than a back rub and bendy straw are on notice.