Yes, we have the same problem as my condition is VERY unpredictable, it even makes it difficult to book appointments of any sort, so I have to have dentist and optician visits at home. What really annoys me though, is that we have a camper van, which is the only way that I can manage to travel any distance, but with a lot of sites you have to book your over nights beforehand, which I refuse to do in case I can't go it ends up costing us a considerable sum of money. This leaves us often having to park up overnight somewhere, where hopefully we won't annoy anyone, but even then, we get 'boy racers' who think it's great fun when they see a camper parked up, to pull up beside us late at night and start playing their music at top volume, or they drive by with their hand on their horn, or in one case, pulled up beside us and then sped off spraying us with gravel. Why do people have to make life so difficult for others? Of course we appreciate that businesses can't afford to save tickets, on the off chance that we'll turn up, as it would cost them money, but on the other hand, it really can be very frustrating when you miss out on things. I really don't know what the answer is OP.
