After Ireland lost to New Zealand in the 2023 World Cup quarter-final, Andrew Porter blamed himself for the defeat. It was a kangaroo court. Only the prosecution laid out a case. For weeks Porter descended into a state of self-laceration.

In the off-season, he cut himself off from the other players. His sleep was thrashed. Fragments of the game danced on a loop in front of his mind’s eye. Not the highlights. There was no forgiveness.

“It felt like a form of sleep paralysis,” Porter writes in Heart On My Sleeve, his stunningly reflective new autobiography, “where you wake up at night constantly thinking there’s something lurking in the corner of the bedroom. A shadow that I couldn’t grasp.”

The only person who harboured these thoughts was Porter. Nobody else had reached that conclusion about why Ireland had lost. In his career, though, this had been a recurring pattern. After big defeats he couldn’t excuse himself. He would shoulder the weight of the loss. “Instead of understanding that I had simply made mistakes,” he writes, “I was thinking that I was the worst player ever.”

In the aftermath of the New Zealand defeat these thoughts reached depths that he couldn’t fathom. He went in search of help.

“Eventually I went to a therapist to figure out and explain why I was feeling the way I was feeling,” he says. “The therapist put it in a really good way that I could understand. Because of the fact that I had lost my mother so young it was like that stress response. It equated to being close to the loss of my mother back in 2008.