I have to say I find something depressingly callous about today's entry. His mother was was so fatigued and ill that she was obliged to be brought home in a cab and was expected to die on the road. Yet he seems more interested in buying a new penknife 
Carole
That's why I think he might have written the diary in stages throughout the day.
Say Mum got home at midday in the cab ... he might have helped her up stairs, tucked her into bed, made her a cuppa, written in his diary.
Then he popped out for a walk while Mum was sleeping and just happened to pass by the penknife shop, so he decided to buy a new one as he'd broken his old one.
Then he went home, made sure Mum was comfortable, checked out his prints, had tea then just before bed wrote in his diary that he'd bought a new penknife ...
What do you think?
Just a different take on the entry.
