I doubt if I'll ever get the time, but if I were younger, I would try to learn the hardware part of it. I've watched guys do it, just get out a couple screwdrivers and 5 minutes and my old hard drive was out of my old computer (never crashed, wanted to save it). But if they add hardware, they have to tinker with the bios, find the right drivers, get them installed correctly. Sometimes that can take longer and you are on their clock :-(.
I kind of envy people who are confident enough to build their own computers and buy their parts off the shelf, just what they want. I wouldn't know what tower to start with and I don't know if my current one has room for any more internal hard drives.
I tried learning DOS and what some of this is, but I would rather put my energy into getting the most out of my software.
I love these little passport external hd's. At least I can figure THOSE out, and you have to watch what you are doing when you are copying files. I have messed up more than once.
ATA, SATA, now I know what the are supposed to LOOK like, but I don't know the difference or what the letters stand for. I'm not ashamed to admit it either.
I build my own systems.. its easy. Just read the Motherboard manual, take your time and if you have questions ask online in a online computer forum, most people are willing to help.