Need some help with the tenses here.
I'm not a native English speaker. In reading Adam Kay's This is Going to Hurt, I've noticed many cases where tenses are mixed together within one paragraph. The book is based on his diaries written when he was a doctor. I'm very confused by the tenses. Can anyone please explain a bit the logic behind to me? Many thanks.
Here's an example:
"Having a poo on labour ward when the emergency buzzer goes off, and within minutes I’ve delivered a baby at crash cesarean section. The second the buzzer sounded I crimped it off, but my wiping was cursory at best, which is why my arse is now unbearably itchy while I’m scrubbed into theatre."