THANK YOU EVERYONE who recommended PHOTOREC! This community is fantastic.

Accidentally flashed a live image (PCBSD, IIRC) onto my 1TB external HDD instead of the thumb drive. Lost years of collected music and movies that night. I learned two things:

1. Don't do this sort of thing in the middle of the night, when you're tired and should be sleeping.
2. dd is nicknamed 'disk destroyer' for good reason.

Before you perform another task on that hard drive, try photorec. You might be able to get a majority of your files back if they're important

I remember shortly after college I was living with a couple of people and one day we all heard “NOOOOOOOOOO!” and went running to see what tragedy happened. He had started formatting the one porn drive he had been collecting on over the last few years.

Make a donation to the testdisk author!

Expecting things to be different.

Installing GNOME on Kubuntu I think, hahaaha.

I got started in Linux about 15 years ago. I'm not skilled nor a techie but knowledgeable enough to make things work. After running endless cracked windows machines I switched to Linux and started distro hopping. But I didn't have enough money at the time to afford a lot of hard drive space.

I remember going from one distro to another while trying to transfer a couple of GBs worth of work on the same drive. Two GB of data was a big deal to me at the time. At one point late one night after about the tenth distro attempt, I wiped an entire drive worth of my unbacked up work. Worst moment of digital loss I ever had.

I've kept double triple and quadruple backups since then .... and I still worry about losing data.

It sounds like you need to learn about disk forensics before you go any further. Check out FTK

I’m concerned at the number of people who boot new OS’s without backing up their computer.

I put my home directory on another partition, because I heard very early on that it can better facilitate distro hopping. That is not the stupid part, that's actually good advice.

The stupid part was assuming that Linux users are identified by name, and that as long as I create a user with the same name as the one on my previous install, things would Just Work.

Im reality, Linux users are integer IDs under the hood. And in my original system, my current user at the time was not the first user I had created on that system. Thus, when I set up my new OS, mounted the home partition, and set the first user to have the same name, I was immediately unable to log in. The name match meant I was trying to read my home dir, but the UID mismatch was telling me I had no permission to read it. I was feeling ballsy with the install and elected to not enable the root user, so I had an effectively bricked OS right out of the box.

I'm sure there was some voodoo I could have done to recover it on that attempt, but I just said screw it and reinstalled.

I wiped my drive with a lot of non-backed-up data on it intentionally because the Fedora installer was too confusing. Lost among other things my Celeste and Minecraft saves, a lot of images, and other stuff with sentimental value.

I've done rm -rf / twice on Fedora installs.

Correct. We are used to look at computers like if they're tools. Actually they're environments.

Reading this thread makes me appreciate Macrium Reflect and my 64TB worth of redundant backup drives even more.

Nothing special, I just kept distrohopping and backing up my home folder to a seperate drive each time via rsync. Eventually I messed that up somewhere, some data was lost. I think that was early this year.
Nothing to major, bit of a nuisance is all. And a grim reminder that eventually you WILL mess up. It's just a matter of time really. So try to minimize the factors that lead to mishaps like distrohopping and be diligent with your backups.