I couldn't have gone another metre

[Maybo]

'Did you see the other buildings?' Palmer asked. He was out of breath as well. 'And I spotted the ground another three hundred metres or so further down.'
Hap nodded. 'I saw. I couldn't have gone another metre, though.'

Source: (Sand by Hugh Howey)

Why did the writer use "couldn't have gone" and not "couldn't go"?

 

[Tarheel]

The question suggests that he considered both options and decided between them. I don't think that's what happened. Instead, he used what he considered natural speech. The person in the story is winded and has to catch his breath. He says something like "I couldn't have gone another step." What he he means, I think, is that he's glad he didn't have to do any more walking.

 

[Maybo]

The question suggests that he considered both options and decided between them. I don't think that's what happened. Instead, he used what he considered natural speech. The person in the story is winded and has to catch his breath. He says something like "I couldn't have gone another step." What he he means, I think, is that he's glad he didn't have to do any more walking.

Why was he glad? Wasn’t that he just couldn’t go down further?

 

[Tarheel]

I think he's happy that he doesn't have do any more walking. He's tired and doesn't want to walk any more. If I was tired I would be glad that I didn't have to do any more walking.

 

[Maybo]

I still don't understand the difference between:
1. I couldn't have gone another metre.
2. I couldn't go another metre.

 

[emsr2d2]

I still don't understand the difference between:
1. I couldn't have gone another metre.
2. I couldn't go another metre.

1 has an implied conditional - "If you had asked me to another metre, I couldn't have done it".
2 is a simple statement of fact - "I wasn't able to go another metre".