Your backpack should weigh less than your doubts. Mine weighed eleven kilos on day one and seven on day three, and the doubts went the same way.
1. Pack half of it, then take out two more things
I carried 11 kg on day one and 7 kg on day three, after posting a box home from the San Sebastián post office, which is used to this and has a queue of pilgrims every morning. Nobody needs three t-shirts on the Camino. Wash one, wear one, and buy a third in Bilbao if you must. The same goes for the book, the second pair of trousers and the camping towel that never dries anyway.
2. Rain is not the problem, wet feet are
A cheap poncho is fine; mine came from a petrol station. What actually kept me walking on the Norte were waterproof socks, or, on the days I forgot them, a dry spare pair in a plastic bag and ten minutes under a bus shelter to change. Wet feet blister, blistered feet stop you, and stopping is how Caminos end.
3. Tape before the blister, not after
The moment you feel a hot spot, stop, sit down, take the boot off and tape it. Every pilgrim who told me this was right; I learned it the hard way at Zarautz, where I walked two extra kilometres on a 'small thing' that then needed three days. Compeed is not a luxury. Neither is stopping.
4. Cash in small villages, cards in cities
Between San Sebastián and Bilbao, cards worked in every restaurant and no albergue. Carry forty euros in small notes for donativo albergues, village bars and the ferry at Pasaia. The cash machine in Deba is broken more often than not, or so the man in the tourist office told me with real sorrow.
5. Say yes to dinner with strangers
This is the one nobody mentions because it sounds soft. The Camino is mostly conversations: a Dutch nurse, a Basque couple in their seventies, two Australians who had walked from Santiago the other way. Every dinner I said yes to gave me something I still carry; every one I skipped to 'rest' I do not remember. Sleep, yes. But eat with people first.
And a sixth, for free: nobody your age is too old. I met a man of seventy-eight in Zumaia who was on his ninth Camino. He was faster than me.