I know, you thought that you could avoid math if you pursued photography. But, there is one math test that all photographers must pass.
For this test, you need to answer two questions:
1. When was the last date you captured an image that you care about? In the equation above, that's value "A".
2. When was the last date you backed up all of your images with a copy stored at a trusted off-site location? That's value "B".
Subtract your second answer from your first to get "C", a duration in days (or go to hours for a higher precision). I know, date subtraction is not so easy, but ... hopefully the answer involves a small enough number for you to do the math in your head.
If the result is a near-zero value, I congratulate you heartily (0 is the perfect score). You are among a minority. If you needed to resort to a date calculator app to solve this math problem, you are in imminent danger of losing something important to you, perhaps an image collection that has taken a decade or longer to create. If your duration-since-last-backup calculation is multiple days, right now is when you need to do something about this problem. It is only a matter of time until you lose the images captured since your last backup – you can be assured that failure will happen.
If you don't know where to start, buy a few WD My Passport external hard drives at B&H, Adorama or Amazon. I have dozens of these drives, have used them for roughly a decade and have had no failures ever (I know, I'm due). These drives are very small (great for portability to the referenced off-site location), reasonably-priced and, with the latest models arriving in 4TB capacities, they hold a LOT of high resolution photos. Simply copy all of your images (and any other important files) to two or more drives and move at least one to a safe off-site location. Best is to use a rotation of multiple drives that insures all copies are never in the same location. Being a bit paranoid (AKA experienced in these matters), I use a double redundancy approach.
Hopefully you sleep better knowing that your images are safely backed up. If something terrible happens, such as a house fire, you can focus on getting you and your loved ones out of the house instead of making a desperate rescue attempt of a prized image collection.
Timely is that after I initially created this post but before I shared it, the SSD (Solid State Drive) in one of our laptops became corrupt.
Again, right now is the time to shore up your image preservation strategy.