Maleness?

Today, hubby took Kate to the dentist because I had to be at the doctor with Tim. Yes, at the same time. I just came home. I asked how things went. 'She has one cavity.'
Me 'Oh well. Did you make an appointment for a cleaning?'
He 'Yes, for Monday at 8:30am.'
Me 'OK, could you put it on the calendar? Which Monday is it?'
He 'I don't remember, but I think it's on this paper.'
He 'Oh, it is not on this paper. I don't remember which day.'
Me '...'

So some Monday, Kate will see the dentist. He doesn't seem to think it any problem that we don't know which Monday. At least I assume he doesn't, since he is at his computer now, not calling the dentist to find out when the darned appointment is.

Is this a male thing?