Reasons to be Cheerful by Nina Stibbe (Penguin)
I have to confess that this is the one title from the 21 books that I had to abandon. I read 20% of it but no more.
I hadn't connected with the characters at all and the dentist setting, including quite graphic details of dental procedures, was just too much for me in light of my own traumatic experiences in the dentist chair.
I think that perhaps if I had liked any of the characters, or had found it at all amusing I might have coped with the setting but it wasn't for me.
I think I am in a minority here as many do find Stibbe's writing amusing but this one just had to be put down.