Back in 2012 or 2013 a friend of mine came to me with their netbook running Windows (7, I think) which had, as Windows computers are prone to do, become increasingly slower. So bad in fact that it took almost a minute for the file manager to open a window. I remember thinking that this must be a hard drive issue. There's just no way that an OS installation can deteriorate that much.
I booted it from a USB live stick with Ubuntu and tried to access files on the hard drive. To my surprise it was snappy and responsive. "That's it," I thought, "I can't allow them to suffer this Windows mess anymore, and definitely not again some time down the road."
"Do you feel like you have to run Windows or would a Linux operating system be okay?" I asked, to which I got a shrug and a "don't know what that means" as a response. I inquired a bit around what they used their computer for, and it was the usual: web browser, word processor, and very little else. Maybe watching local video files sometimes. I can't remember if they did any torrenting, but it didn't really matter.
I installed Ubuntu on it and sat down for about fifteen minutes showing OpenOffice (if I recall correctly LibreOffice wasn't formed yet, but if they had it was that) and how to read and export docx files. I showed where the web browser and VLC could be found, and as I said I can't remember if they did any torrenting, but transmission was in the default installation and easy to use anyway. One thing I was very clear about was that they can't download installation files from the internet and run them, because those are usually for Windows and just won't work.
It turns out they never needed any programs beyond the default installed ones. Some two years later they came to me with a brand new computer, when the netbook had given up, and asked me to install Ubuntu on that one too. They'd gotten used to it and liked it better than Windows.
-- CC0 Björn Wärmedal