'Just imagine it's Mt Maunganui' is my mantra - what I conjure up to combat the mental struggle ahead.
And the first four-and-a-half hours are perfect - a few small climbs, plenty of rain but no snow. The scenery is breathtaking.
It's not crowded, alternating between path and road, passing through a few small villages, we see only a handful of other pilgrims.
For a while I even wonder if the big climb will come, or if we'll just follow a valley through the middle.
Of course I don't really believe this, but it's amazing what the mind does.
At the 21km mark I start to go and at 22km my energy levels slump - 'the climb' arrives and life as I know it takes on a whole new dimension.
Lisa sees it and goes for the chocolate - I just haven't eaten enough. But it's too late.
'Just imagine it's Mt Maunganui' isn't doing it for me, and I'm gone.
I think about the The Tour de France - it comes through these parts. Lisa's Lance Armstrong and I'm The Pack. I need EPO.
And I think of Lisa Tamati, NZ's ultra-distance runner, about our vast reserves of untapped energy. I'm searching for mine, I'll take anything.
My heart is racing and I'm worried about a heart attack. It's pissing down and I don't even notice.
I won't give up but it's a devastating hill - 3km, and steep. Up, and up and up... and the end's nowhere in sight.
At some stage in the late afternoon, I get the 100 metre call from up ahead. All nightmares come to end. I make it, and collapse.
I'm lying prone atop the Pyrenees, with views in all directions. Overwhelming relief floods in. And it occurs to me we've crossed the border, we're in Spain. Voila!
Our hostel in Roncesvalles is 1500 metres straight down the mountain on the other side and 30 minutes later I'm in it, asleep.
Later, I'm revived for the pilgrim dinner, three courses including including vegetable soup and bagette, trout and chips and yoghurt for dessert, with unlimited red wine. Nine euros.
The gradient for day two is a 500m decent over 22km, and day three to Pamplona is flat.
It's just what I need.
Route marker: 27km down, 748 to go.
* Simon Winter is a former nzherald.co.nz news editor. He and partner Lisa are following the sun through Europe. They're finding the weather somewhat colder than expected.