This will be my 3rd attempt to post this here, I don't know why it wouldn't work earlier.
Anyway, we went trekking with my dad and a friend of mine some years ago to Northern Finland. We travelled to the starting point by bus and had to walk all the way back for a total of about 80 km. We all had to sleep in a tent in the forests and carry all the food and supplies we needed for the whole trip with us.
As our 3rd night there was approaching, when we still had about 25 km to go, I was just so tired of sleeping in the uncomfortable tent full of mosquitoes that I decided against stopping and sleeping, but instead keep walking all the way back without rest.
It was quite insane experience, I kept walking all night without any food with me, and the last part of the route was almost completely climbing up and down hills which was very exhausting. The closer I got the more painful walking got for me and I kept nearly falling asleep in the forest.
I eventually after a lot of struggling and suffering got back to our cottage at 3 in the morning, having walked nearly 40 km in a single day. I fell asleep instantly the moment I got on my bed, and my legs hurt for weeks after that.
Even though it was rather painful in the end, I don't regret making the decision to continue all the way back as it was a very interesting experience and not something everyone does.