I have an external hard drive, which contains a duplicate of everything except my photos and videos. I also have a copy of most things on my personal drive on the server at work. I don’t back up the external drive as often as @johnpowell, more like every other month or so.
In a way, it’s more a peace of mind kind of thing, because I almost never go back and look at photos from the past. A few months ago, I did this collage of my kids, with a head shot of them from April of each year of their lives. It’s when the azaleas in the back are in bloom. But that’s the only use of past photos I have made in years.
I do have some past files that I looked at recently. But most of the past files of interest are my Quicken files and some stories I wrote back when. None of those stories is actually interesting to me except as a reminder of what I did.
My main concern is all the physical media I have—letters going back 30 years or more; slides going back nearly as long. Prints and negatives.
But I almost never look at them, either. So I think their presence in my life is a comfort thing. I know that if I need to, I can look back. If the house burned down, I would be quite upset about the loss, but I don’t think it would make a substantive difference.