I thinks part of any long walk that you’ll have a bad day.
Our bad day on our self devised walk from Swansea to Conwy three decades ago was from Dolgellau to Maentwrog - the tent was heavy after a night of rain, packs weighed a ton, and towards the end of the day we ended walking down the side of the busy A470 near Trawsfynydd, were turned away from a snobby caravan site, and another camp site turned out to be defunct, an excrement plastered field.
We were close to home though, so staggered an extra few miles down a quiet lane to a favourite pub of ours, The Grapes in Maentwrog, had a few beers and an excellent meal, and took a taxi home to Dolyyddelan, only 10 miles away. Returned the next day by bus and walked home with feather light day packs, then had a triumphal last day galloping over the eastern flanks of the Carneddau to Conwy, light packs again, felt like we were walking on air!
PS - we were using Petzl headtorches way back then