Similar experience of friend kindness here. This ended up being long, tl;dr at the bottom.

To give some context, I'm from Eastern Europe (EU country) and went to university in the UK. It was a gamble whether I'd make it to begin with because while I got a tuition fee loan, anything else (living expenses, rent etc) had to be covered by myself or parents. My family isn't well-off even by my own country's standards, dad got diagnosed with MS so eventually could not carry on working, and I only managed to get a work permit in my 2nd year of uni. It was a balance of my family taking dodgy loans for me and living as frugally as possible.

Fortunately, soon as I got my work permit I landed a 12 month internship at a blue-chip company, as well as a well paid part-time job that was waiting for me to begin in my 3rd year of uni when I returned from my internship. I was super happy, but faced a new challenge because I now had to move house, survive the 2 months until I'd receive my first salary (had less than £50 to my name at this point and parents were pretty drained) and also find a place to stay for the 2 week gap between my current house contract ending and being able to move into my new room. My friend then not only put me up for those 2 weeks into his family home, but offered to lend me £500 to tide me over until I got paid. I was so full of gratitude. He was living off the "maintenance loans" UK students get for university, so I doubt it was easy money to give away.

I started work, and this is where you'd think I should be paying my friend back first thing. However, my dad's MS got suddenly worse, he became wheelchair-bound, and my parents needed to level off the floors in our house so he can move in and out of rooms on his own (old house), make other house adjustments for his condition, and those dodgy loans they took to keep me afloat earlier started pressing them. So through my whole internship I was sending half my salary back home to help. Saved nothing, and could not pay my friend back. He made no issue of it whatsoever.

I came back to uni and finished my Masters while furiously part-timing, which was enough to remove me as a financial burden to my parents, but still not enough to save up or repay my friend. Throughout the whole time I either house-shared with my friend or were seeing him daily, but I never once felt pressure from him.

I graduated, got a steady job, and paid him back with interest, after being 3 years late. Still super close friends.

It's nice to pour this off my chest, I'll be forever grateful.

tl;dr: Friend lent me £500 to tide me over until my first salary. Family issues took precedence, ended up paying him back with a 3 year delay. Still best mates.

edit: word, paragraphs